"I have a lab of 17 Dual 2.7Ghz G5s that are all now leaking their coolant - all at once. A significant number are dead in the water and the rest are just holding on right now. Symptoms are wide-ranged but will include fans spinning wildly, machines shutting down when they heat up, greenish liquid leaking from the case, and if you are able to look, crystalized liquid forming where the CPU meets the heatsink as well as corrosion of all the metal surrounding the CPU module.
Eventually, the machines just stop working altogether necessitating a replacement of CPU, Logic Board, Power Supply, and two smaller parts. (If you spot a coolant leak DO NOT keep using it.-Mike) In one case the power supply started to shoot off black smoke and then died. (some others noted this also when the coolant leaked into the power supply.)

As of yet, Apple has been fairly unresponsive in fixing or replacing them and I am now working on making this more public. I am curious to know if any other people are having this problem. I know of 3 other cases outside our own lab here. The machines in our lab were the first of the dual 2.7s - they were bought right when they came out.
-Zach M.
Systems & Network Administrator
Instructional Development at UCSB"

Latest Reports on PowerMac G5 Coolant Leaks: (later mails first)
If you've had a G5 tower that leaked coolant, let me know the details. (Model, how long it was used before leak occurred, if it was repaired by apple under warranty or not, etc.) Below are replies to the Aug 27th, 2007 news post (copy above) from other tower owners that have had a leak. Although it might be rare overall (of the total shipped), if you have a liquid cooled G5 especially with some age on it, it may be worth checking periodically for any sign of a leak to catch it early and minimize the damage. (BTW: Please note your G5 tower model/speed, when it was purchased and if yours has the (original) Delphi LCS or the Panasonic LCS used in some later models - see photos of each LCS below. Thanks!)

(added 5/2/2008)
" My G5 also suffered from the infamous G5 coolant leak. My case is not as castastrophic as some of the others posted here, but still, it isn't pretty. I have a dual G5 2.7 GHz machine, purchased in May, 2005. It was my "switcher" machine, as I came from the Windows side. It has been my daily machine for personal and side work in web development and audio production. And up until recently, it was rock solid reliable, never so much as a hiccup.

A few months ago, it started the habit of not wanting to restart, such as after a software update. The symptom was the normal chime followed by a black screen (not even a gray or blue screen), no HD activity, nothing. If I let it sit like this for a while, eventually all of the fans would start blowing like a jet engine - loud. If I forced a restart a few times, I could usually get it to start up. I've run every hardware test, every diagnostic I've been able to find, and everything checks out fine.

So last night, after doing my triple backup routine (I'm paranoid), and then some updates, I started into my reboot sequence, just expecting to have to go through the usually 3 or 4 restarts to get it to boot up. After about the 20th try, it was becoming apparent that something was really wrong. About this time I noticed a few seconds after the boot up chime, a red LED was illuminated inside the case. I could only see it by looking through the cheese grater front of the case. It appeared to be on the main logic/mother board, about in the middle of it. The LED is not visible directly from the side if the case is opened up because it sits behind the upper left corner of the multiprocessor enclosure.

I began searching for diagnostics codes for this LED, and ran across your list of other G5 coolant leak suffers, along with a slew of other hits reporting the same. So I went back and looked inside my case, and could what looks like a small spot of dried milk in the bottom of the case in the lower right corner of the G5 cpu enclosure. It looked much like the first picture at http://www.fusina.net/G5_coolant_leaks/gallery.php While it didn't look like much, it was indicative that something had indeed leaked inside, nonetheless.

I contacted Apple Care, ready to state my case, thinking that my Apple Care had already expired (I thought early April), and here it is, May 1. Fortunately for me, I have 5 days left of Apple Care. Talk about timing being everything! Usually I'm five days on the other side of the expiration date. I described the problem and they logged a case number, and asked that I take it an authorized repair center or Apple Store, I chose the latter. They looked at it and pretty much confirmed everything I suspected. Upon a closer inspection, it is obvious that the leak has been going on for quite some time. It has corroded large areas under the processor enclosure as well as most of the top of the power supply, and the logic board is damaged as well. Estimated repair costs are around $2000, but in my case, being covered by Apple Care, no costs to me. The tech said that this was the third one he had in this week, although he had only ever seen a few prior to that.

They have the unit now and they think they can fix it. He said that he thought they'd be able to get the necessary repair parts (logic board, multiprocessor unit, power supply, and case might need to be replaced depending the extent of the corrosion damage. However, if other reports hold true, that might have been optimistic musings on the technician's part. Estimated repair time is 3 - 5 days, but they won't have full handle on the extent of the damage until some time tomorrow.

Thanks for keeping up with this issue. I'll update you on how this one turns out. Personally, I'm hoping for replacement with a Mac Pro, because now I'll never trust a liquid cooled G5 system ever again.
-Jeff B."

I have one of the first (2003/Air Cooled) Dual 2GHz G5 Towers. It's not been used that much over the years (daily work systems have been PB G4 and a 2007 refurb AL iMac 24in) but my G5 has been rock solid (no issues, no random shutdowns, etc.). I'm thinking of selling it now and getting a (refurb) 2008 Mac Pro. I don't have an ebay acct but if any readers (in the USA) are interested in a Dual 2GHz G5 tower w/3.5GB RAM, two HDs, DVR-109 and (original build) ATI X800 (also have a spare Apple Nvidia 6800Ultra card) make me an offer.

Pump related Fire? (per the comments not a leak per-se but posting here as a FYI)

(added 4/16/2008)
"Hi Mike, Spotted a few more stories on PMG5 cooling system failures so I thought I would share the results of an experiment with you.
An existing customer of mine called in a panic to say that his Dual 2.7Ghz G5 was on fire. Yes.... on fire. The Mac was delivered to me the following day and it had clearly been burning. The PSU was my first port of call but I was amazed to hear all the right noises when i plugged it in and pressed the power button. Even got a boot chime! So, I put on my Sherlock Holmes outfit and, comedy sized magnifying glass in hand, set out to solve the mystery. I stripped the G5 down to a bare configuration and noticed that 3-6 seconds after pressing the power button, 2 red LED's came on behind the processor module. One on each processor card. These LED's are the overheat warnings. This pointed to a problem with the cooling system. But, I could not figure out why the Mac gave a boot chime each time it was powered up. Surely the processors had to be frazzled. The smoke damage inside the unit made this pretty much guaranteed.

With the processor module extracted, the cause of the fire was clear. The cooling pump had burnt itself out. And I mean BURNT OUT!! A hole around 15mm, with melted edges, gave a clear view of the charred mess inside. The smell from it was choking. I knew that the proc module is sold as a complete unit and is prohibitively expensive to replace. However, I didn't give up. The boot chime made me think that the processor cards were actually ok. I spoke to the customer to get permission to experiment with replacing the pump. He agreed. A bit of research on the net brought up a page with the info I needed. Although the pump in the G5 is a unique model, unavailable to Joe Public, it is based on a freely available pump. The Laing DDC-1T. The model in the G5 is a DDC-1V. I ordered up a pump (£45 compared to £650+ for a complete proc module from Apple). (If a G5 CPU module is swapped they also do a thermal recal.-Mike) When it arrived i screwed the new base section onto the top part of the case (the part connected to the rubber hoses, which I left connected as it was impossible to remove it without bursting the hoses) and hooked it up to a separate 12v power supply. The pump spluttered into life and I let it run for a few minutes until the trapped air made it back in to the radiator. Careful handling of the processor module with the old pump removed resulted in very little fluid loss from the sealed system. Moment of truth time had arrived!

Boot chime.... hard drive activity.... boot screen.... desktop!

Hardware Monitor showed that the proc temps were high. I put this down to the thermal paste being almost boiled off of the heatsink prior to the thermal management shutting the system down when the pump failed. I stripped the module completely, replaced the paste and soldered on the Macs own pump supply cable. This would be the final hurdle as the pump failure may have damaged the logicboard. It didn't. The G5 booted up fine with the pump doing it's job. Hardware Monitor showed a 15 degree drop in idle temps. Stressing the Mac didn't cause any concern. I cycled the system from cold to maximum stress to settle the paste. This resulted in a drop of another 3 or 4 degree at idle. Even removing the front pair of fans didn't cause a thermal shutdown.

I topped up the coolant with some distilled water. (FYI - An earlier report below also comments on Leak repairs/O-rings and includes a link to the MSDS on the OEM Delphi 151 Coolant fluid, which is distilled water + a small amount of Propylene Glycol and therefore will have a higher boiling point than pure water. (As well as lower freezing point, but freezing should not be an issue in typical use environments.)-Mike) It took around 45ml. (That's appx 1.52 oz. The Delphi MSDS notes a -max- of 6 oz., but that doc may not be specific to the G5's LCS, and you mentioned a top-off so I assume most of the OEM fluid was still intact. I'd check for any air in the system also.-Mike) The G5 then went back to the customer for real world testing. He uses the Mac with Final Cut Pro so i did worry a little that this may cause it to overheat. That was 2 weeks ago. Just got a mail in from my customer reporting no problems at all. The G5 is acting exactly as it did prior to the pump fire. One happy customer!

(Never heard of a fire related to a pump failure before (I asked if he took any photos). (Some rear horror story pictures linked in some previous posts - rust, damaged PS, motherboards, etc. from those that had a leak over a long period of time undetected.) So there was no actual leaking of fluid inside the case?-Mike)
I did have a couple of pictures on my iPhone. They are no longer there and they are not in iPhoto. I also don't seem to have emailed them anywhere. I though maybe a leak into the workings of the pump could have cause the fire but when I fully dismantled the pump it was clear that there was no breach between the casing parts. The circuit board was completely gone in one corner and the copper track had lifted off over the whole board. It really was something I should have photographed and documented. However, I get so busy here that taking pics is the last thing on my mind.

(I asked to confirm no coolant had leaked inside the case)
There were no signs of leakage anywhere at all. That amazed me. When i removed the pump only the contents of the pump enclosure leaked out. I purposely did not remove the filler plug in order to maintain the slight vacuum that would have been created by the fluid trying to leak out. When I was ready to run the pump I removed the plug to allow the air to migrate through the tubing into the radiator. I then gradually added the water over a period of time until it would take no more. As the pump circulated, the air made its way to the top of the radiator.

However, the impeller of the pump is magnetically rotated with the circuit board sitting some distance away from the enclosing section. The following link shows the inside of the model of pump I used. The first pic shows the casing with mounting wings. The G5 pump didn't have these so i removed them with a utility knife to allow the unit to fit in place. The G5 pump also had a further base extension part that was, to put it simply, weird!
http://blog.pixnet.net/windycj/post/6590735

The additional base section housed 4 springs that pressed against a curved piece of plastic that covered the green circled area on pic 2. The screws you can see on that same pic were disposed off and the longer original screws were reused to pull the whole thing together. I can only guess that this spring section aids acoustics.

Look at pic 3. Imagine a straight line from the point where the black wire is soldered on running diagonally upwards past the circular black plastic bit. That whole section was dust. Gone completely.

The G5 pump is also connected differently. The terminals are a mirror image of what you can see on the pump at the link above.

I have looked at the syringe i used to refill the system. The measurement is in CC and i refilled the syringe 4 or 5 times to completely fill the system again in 2 stages. The syringe takes 4 CC's when full.

I used gravity to get rid of trapped air and ran the pump connected to an external power supply for a while until it ran quiet. Initially, i could hear when it was trying to pump air. I already knew the make up of the fluid and knew that distilled water would be fine. (If only a small amount of top-up was needed it should be fine)
-Kevan G.
www.fixmymac.co.uk"

(added 4/14/2008)
"We have two Power Mac G5 (Early 2005) 2.7GHz DP water buffaloes. Purchased 05/13/05 without Applecare.
Water buffalo-1 has had a slow leak for 6 months, nothing has burned up yet but we have had some heat related shutdowns aka "Thermal Events".
Water buffalo-2 is just now showing signs of a slow leak, corrosion and discoloration in the rear on top of the power supply.

I had both units evaluation by an Apple Certifed Tech (my son) and he told me that Unit-1 need a new power supply, logic board, and MultiProcessor with LCS about $1800 in parts plus labor. Unit-2 should just have the MultiProcessor with LCS replaced, about $700 plus labor.

I was not happy, but I had to take unit-1 out of service because it was blowing large amounts of very hot air. We feared it might go up in smoke. I called Apple support and after I explained the problem I was passed on to a G5 specialist who proceeded to interview me with questions like:

• Were your or anyone else injured by the machine?
• Was there any smoke?
• Was there a fire?
• Was any other equipment around the machine damaged?
• Was there any odor?

After answering all of the questions I was told that I was responsible for all the repair costs.
I replied the since I did not have AppleCare on the machine that I might be responsible for the cost to repair the coolant leak but I should not be held responsible for the subsequent and consequential damages caused by the bad design of the machine, the power supply is under the cooling system, the CPUs are part of the liquid cooling system, the logic board is damaged due to overheating due to lack of coolant in the system. I explained that the leak was due to a faulty $3.00 o-ring and that I would be fine paying the $3.00, but Apple is resposible for the other damages.

The specialist had no choice but to agree with me and he went to the "G5 Champion" and presented my case.

Apple has agreed to grant me a one time exception and pick up the cost of the repairs to Buffalo-1. But they have asked that I pick up the cost of fixing the leak on Buffalo-2.

Apple has sent most of the parts to the service tech except for the two MultiProcessor with LCS, one I am buying the other Apple is buying. It is projected to take two weeks to get these parts. The tech (my son) thinks they may not have any 2.7GHZ MultiProcessor with LCS units. He has been able to get 2.5GHZ units for other customers.

I have thanks and praise for the specialist Eric H. who went to bat for my case with the higher ups at Apple, that we never get to talk to. I still believe that Apple should institute are recall/upgrade program for all liquid cooled machines that show any signs of leakage. And if you cant get the parts ask for a credit toward a new machine.
-Fred C.
General Manager
TheTroupe Modern Media Design & Production"

(Added the report below here and on the older page on G5 Tower Random Shutdowns - from the list of replacement parts it sounds like there was a leak, although the absorber mat may have masked that from his initial inspection.)

(added 4/7/2008)
"I purchased a Power Mac G5 Quad (2.5 Ghz with the Delphi LCS) back in December of 2005 along with an AppleCare warranty. (So it's still under warranty then?-Mike) Not sure if I had a leak, but CPU Temps on Processor B were consistently a lot higher than processor A by on average 50celsius (this started around November 2007). I usually use this machine for Aperture, Adobe PS, and also as my World of Warcraft machine. About a month later (December 2007) I started experiencing random forced sleeps (sleep or shutdown?) along with a red LED visible from the front whenever playing WoW or using Photoshop. I opened the box up and checked for leakage or signs thereof and wasn't able to find anything.

I brought my Power Mac into the Apple Store after making an appointment in early January and after a preliminary check (and my showing them excerpts from my system log showing thermal runaway and stats) (system log entries on "PMU forced shutdown, cause = -122" and/or "thermal runaway" messages were also noted by others here on the page on G5 Tower Random Shutdowns.-Mike) was told that a new Logic board, power supply, cooling unit, and processors needed to be ordered. (sounds like there was a leak if all those components needed replacing) The store quoted me a turnaround time a 7-10 business days to allow shipping time for the parts and to test the system. A month went by and I hadn't heard from the store (Thank GOD for my MacBook Pro), so I contacted AppleCare to get a status check on my repairs and was told that the part that they were waiting on needed to shipped from Washington and was being overnighted to the store that afternoon. The store contacted me the next day and left a voicemail on my phone requesting that I call them back. Long story short, they replaced my G5 Quad with a brand spanking new (Mac Pro) 3.2GHz Octo 8800 GT. :-) that put a HUGE smile on my face, needless to say!
Yeeehaw for Apple. Now I know why I have been and always will be a Loyal, Apple Fan!
-Adam"

I'm impressed that they've replaced some out-of-warranty systems like this (and giving higher optioned Mac Pros than base for those that had higher end G5 towers apparently), although some didn't get a no-cost system swap, more than a few have especially over the last 6 months. (One recent report noted he had to pay the est. repair costs to get the new system, but some were offered new systems at no cost.) In some cases in the past, not giving up on the first response (pressing for a replacement/repair at no cost) resulted in getting a new system replacement.

(added 4/4/2008 from 4/3 mail - updated 1PM ET 4/4)
"Just had a leak this morning.
Dual G5 2.5 purchased mid 2005 with the Delphi LCS.
Machine wouldn't boot this morning. Opened it up expecting to switch RAM around and noticed liquid coming from the bottom of the machine.

I called Apple Care. They first tried to say that it was out of warranty to which I said that it was obviously a known issue with the cooling system. After a short check with a supervisor the rep set an appointment for me at the Apple Store.
I will write more about that experience tomorrow.
Thanks for keeping this log. I have printed it out and am going to take it in to the apple store with me.
(he later wrote)
Hi Mike, here is a quick update. Dropped the machine off last night. I was told that it would be repaired or replaced free of charge (UTC Apple Store in La Jolla, CA ) The repair ticket they gave me shows $0 so I am optimistic. 5-7 days till I find out but I will keep you posted.
Thanks!
-Rob
Producer, TD Media"

(added 3/31/2008 from 3/29 & 3/30 mails)
"I just took mine to the apple store. The estimate is almost a Thousand dollars. I am going to contact apple on Monday and see if they will do something as the store told me there is no recall and the can't give any credit unless apple ok's it.

It was purchased nov 2004. I used this machine 6-7 months a year as it is in my other home in AZ. Its a G5 2.5. I had applecare for three years. So the machine has only an actual use of less than two years.
(the next day he wrote)
"I just talked to applecare today and they are replacing my g5 with a Mac pro 2.8GHz. They are matching all my upgrades that I had on my g5 that I bought from them. I can't commend them enough, what a great company to deal with. They recognize they had a problem and doing their customers right.
-Dick"

(added 3/26/2008)
"I wrote in earlier (2/14/2008) about my G5 2.5GHz leaking coolant. Apple store said they could not get the parts needed to fix it, and would replace the whole computer for the price of the part required. So I'm getting a new Power Mac (A Mac Pro I assume (like some other readers have - for free even). The cost to repair some leaking G5s has been quoted at over $2000 at times (when leaks caused damage to CPUs, Logic board and PS for instance - if not caught early.)-Mike) for $830 which is pretty cool considering I am 3 years out of warranty. Some of my faith in Apple isrestored! (Now if only they wouldn't habitually rape us on RAM prices.) (You can save a ton of ram prices here - for instance 4GB (2x2GB) 800MHz Mac Pro RAM upgrades for $192.50 and 4GB (2x2GB) 667MHz Mac Pro RAM for under $150 (as Apr. 4th, 2008). Also check the SATA Drive prices there.-Mike)
(he later wrote)
I forgot to thank you for keeping track of all these Coolant leaks. It really helped me get my arguments to apple ready even though I didnt need to use them in the end. As it turned out they graciously, maybe even cheerfully, gave me a new 8 Core Mac pro 2.8GHz with 320g Drive for $800. Comes with warranty, keyboard etc too.

I was surprised that they quoted the cost of repairs at only $830 after reading your reports. Maybe my motherboard was salvageable, or maybe they just picked the number at random so they wouldn't have to give it free.

Interesting tidbit; I brought the G5 to them with no Drives in it. They need me to bring a drive in to send back with my Dead computer... Any drive will do she said - So I'll give them an old 10gig drive I have lying around. I'm typing this from my new computer. She asked that I bring my drive in whenever convenient. They were very nice and seemed a bit pleased that I was catching such a break.
-Chris"

Some (not all) readers here have noted getting (totally free) Mac Pro replacments but that was before the 2008 Mac Pro model was intro'd - and sometimes it took more than one call (i.e. not giving up on the first try/response.)

(added 2/15/2008)
"Hi Mike, Just another report here of a leaking G5. One of our six 2.5GHz G5s went south about two weeks ago, and aside from a dead power supply, the Delphi pump leaked all over the place. After a call to Apple and Small Dog both, I got the machine into the system for warranty exception replacement, but the CPU unit is out of stock until 03/01. The other units haven't exhibited any issues thus far, knock on wood.
In any case, the Apple rep/tech was incredibly helpful and went the extra mile to contact me directly twice.
(later today he wrote)
Quick update to that previous note. Small Dog called me yesterday, and Apple had fast-tracked the part, and SDE had done the repairs already. Just have to pick it up!
-Bob M."

(added 2/14/2008)
"Add me to the list of Coolant leaks.
I have (had) a Dual 2.5Ghz g5 which died on me today. I didn't know it was a coolant leak until I lifted it to bring to the service centre. A green liquid dribbled out the back of it. it's 4 years old and out of warranty. The Apple Repair guy said he'd never heard of Coolant leaks, but he seemed unfamiliar with liquid cooling so he may have been new.
Bought the mac in 2004 I believe, when they were just coming out and in limited supply. Waiting for a quote to see how much it'll cost to fix.
-Chris"

Some lucky owners (that often pressed after being turned down) last year noted getting a Mac Pro 2.66GHz system replacement. (Often repair parts could not be procured, at least in a reasonable time.) Depending on what's damaged, costs (apple parts prices) can be very very high (making repairs impractical unfortunately).

(1/14/2008)
"Power Mac G5 DP 2.5Ghz, 2.5GB RAM, Dual 160GB HDD's
Purchase Date: Mid Jan 2005
Green Sludge and Black Smoke Date: Mid Jan 2008

Am self employed and have used this liquid cooled Power Mac as my main machine until yesterday. It has been unfaltering except for the big-blow that has happened (in pocket and the spirited affair of purchasing Apple!) If I'd purchased a Apple Care warranty at date of purchase, it would have been covered just by four days!

Sounding like something was shorting out, i tried to remove power cable within a few seconds. The machine shut down with smoke, then yellow-green coolant flowed. I am expecting the HDD's and RAM and MOBO to be OK.

The machine's performance has been stunning, good quality and have had experienced exceptional performance. However was wanting to hang onto this machine being PPC, than upgrading to Intel as Adobe Creative Suite (CS2) and other related web design apps seem to outperform the memory hungry CS3 on Intel, and would have upgraded to an 8 Core in at least another year or at a point when Leopard had 4-5 software updates!

Apparently Apple are leaders in design, but who would make a condensing radiator and place this ABOVE a power hungry PSU... It is pretty obvious about water and gravity,,, and power and combining these will lead to trouble...! What angers me more is to fix, Apples motherboard is NZD $2000, a PSU is NZD$400 and labour etc more than three quarters of the prices of a new machine. And rather than having an under side access port to remove the PSU, you have to remove every component in the box to get to it.

From a business decision, i guess Apple have just increased their annual turnover by 50% ! But it sucks that they market their products as superior, but my crappy old Compaq for NZD $1000 has out last this Powermac by 4years with no user intervention.
regards, Samoir
New Zealand"

(added 12/24/2007)
"We have about 40 dual G5's in my group at work, primarily dual 2.5's. Probably less than ten are 2.7's or dual core. There have been only three leak related machine fatalities so far, so I've had a bit of trouble getting people interested in looking for leaks. I believe most of the 40 are about out of Apple Care. We had one of the leaking 2.5's replaced with a stock Mac Pro Quad 2.66. The other two were out of warranty and probably no one pursued it.

I recently located one of the two machines that had extensive out of warranty damage, but didn't have time before Christmas break to look at it to see which cooling system it has. All three remaining G5's under my control are using the Delphi made in China version and I saw no leaks.

I'll probably keep one of my G5's for use as an admin machine. The other two are being replaced with Mac Pro's in our normal progression of testing our software primarily with the latest hardware. I'm somewhat concerned about using a liquid cooled G5 for my admin machine because I really don't want the added risk of a catastrophic interruption.

If I keep one, I'm thinking of laying it on the removable cover side and running it that way. Is there some reason no one has suggested that? I think that would prevent the liquid from running onto the mother board or power supply. Hopefully if the severe leak were to occur I'd just be alerted by the racing fans and would have enough warning. Any thoughts? Thanks for your work
- Rick"

One thing that comes to mind is possible problems with CD/DVD discs (does drive have retention of discs in that orientation). Some drives do.

Another reader's notes on Leak Repairs: Although many didn't realize they had a leak until extensive damage was already done (Pwr Supply, Logic board, etc.), for those that spot a leak early here's another reader's info on the o-ring repair. (FYI - An earlier report below also comments on Leak repairs/O-rings and includes a link to the MSDS on the OEM Coolant fluid.)

(added 12/6/2007)
"We have several G5s with leaks. All are easily repaired by replacing the O ring behind the waterblock cover. You can get the O ring from "Grainger" It takes me about 1 hour to change it out.

If you can't see the leak, remove the G5 aluminum cover by using an exacto blade to cut away the outer rim of the gray plastic rivet (flush) on the top of the cover and push it thru then slide the cover to the left. Just feel the black pad for leakage. (this is how we found it, by touch).

There are 8 - 2.5mm hex bolts along the outer perimeter of the waterblock assembly to loosen and then gently rock it back and forth to free it. turn it over and remove 6 of the eight phillips head screws (2 only hold a stand off post which doesn't need to be removed). Then remove the 4 hex bolts at the center. It is easier to remove both CPUs at the same time. Now just loosten the four screws holding the waterblock cover (these are very tightly secured so get a very good screwdriver so you don't strip them).

Apple only sells the complete unit at a cost of $550 with exchange and the O rings set us back about $12.
(I asked for more info such as the O-Ring part number, "Grainger" contact info and if the o-ring was for the Delphi or Panasonic LCS - I suspect Delphi as they seem the most leak prone, although any LCS can leak over time.-Mike)
The (O-Ring) part number is AS568A-026 ($6.00 each) (See later comments below for other O-Ring info.-Mike)
-K Phillips "

He didn't reply with company info but I think the source is http://www.grainger.com - searching there for P/N AS568A-026 today shows a hit - $6.59 ea. currently. I asked again if his system had a Delphi LCS or Panasonic (Delphi I suspect) - I sent him links to an earlier post below with pictures of the Panasonic LCS and links to Delphi LCS pix.
He later replied:

" My one of my helpers here pointed something out that I did not mention before. We have 31 G5s - all but one are 2.7GHz, the other a 2.5GHz - both types have Delphi cooling. But we used a different O-ring's for the 2.5GHz (A Quad (2 Dual-Core 2.5GHz CPUs)? Dual Pumps?-Mike) (he later replied "One Pump" - so I'm assuming that's NOT a Quad.-Mike) It is part #AS568A-123. It uses a thicker O ring. sorry for the mixup. It might be wise to open the waterblock first to verify the thickness of the O ring needed before ordering. #026 is 0.070 and #123 is 0.103. And yes I purchased them thru www.Grainger.com.
-K Phillips "

LOL - This so typical of my day... (despite requests on the web page email link, hours every day are spent repeatedly getting missing info one bit at a time, repeated mails over and over asking for missing details/requested info, etc...) A big Thanks to those that do take the time to send -complete- info from the start.

(added 11/21/2007)
"Apple Replaced my (leaking) G5 Quad with Mac Pro
(several other readers previously reported getting a Mac Pro replacement also, but not all were so lucky and I don't recall anyone else getting an 8-core model-Mike)
I had a G5 Quad that started acting funny in July, and after extensive troubleshooting, I finally concluded it had nothing to do with anything I did (factory config: G5 Quad/1GB/7800GT/250SD/AP/BT). I took it into the Apple Store at the end of August. I heard nothing from them for over 3 weeks and called for status. They claimed that they couldn't locate a new CPU cluster. They wondered why I wanted to stay on a PPC and they offered me a 3 GHz Mac Pro (they felt bad about it taking so long, and that I was "losing" money from delayed wedding work, etc). After some discussion, I decided it was for the best to migrate to the Intel platform and I offered to pay for some extras. They ordered a Mac Pro 3GHz 4xC/4x1/X1900XT/500SD/AP/BT.

To our surprise, the factory shipped a MacPro 3GHz 8xCore/4x1/7300GT/500SD/AP/BT directly to me. I called the Apple Store and I wanted to know if I had to return that computer (8-core). They talked it over and decided that they wanted me to keep the computer and they ordered me the ATi X1900 XT. We have no idea what happened. The serial number was registered under my name and on the current Apple Care warranty (I still purchased a new one to get the full 3 years). Some how the factory got something mixed up (Monday morning computer?).

While they were swapping the graphics cards, I chatted with one of the Geniuses and got an admission that there is an issue with liquid cooled models (not just Apple) and they were (quietly) offering to exchange failing units still under warranty with Mac Pros. From Apple's stand point, the cost or replacing the G5's with MacPros has to be a little cheaper, but more importantly, a brilliant PR move where they don't really admit they have a big problem, just quietly make it right for the customer and avoid any real media disasters). From the stories I'm reading here, the experiences are widely varied.
-Les M. "

As you can see from earlier reports below - some were offered a new Mac Pro instead of a repair (repair parts sometimes cited as an issue also) - in some cases even out of warranty leaks were covered, while others had no luck. But in several cases after suggesting they not give up on the first refusal, sometimes later follow-up reports said they had better luck after pressing the issue. (As always YMMV - especially on out-of-warranty leaks. I really wish Apple would post something official on this.. preferably a warranty extension program as has been done on some other products.)

(added 11/21/2007 from 11/17 mail)
"I've got an Early-2005 Dual 2.7 G5 that worked well for about 1.5 years, until it started exhibiting problems during reboot. The screen(s) would go blank and stay that way, and then the fans would be off to the races. I'd have to power off and wait. Cold starts sometimes took hours and many attempts. I started monitoring the temps and could see it was excessive now and then.

The other day it fried. Poof! Smoke and stink. My Applecare had run out just months before. I noticed the liquid leaking as I carried it into the Apple Store. The genuis-bar dude quoted me about $800 for the CPUs and power supply. Being a techie, I knew it would be more. I chose to bite the bullet and buy a new $6000 unit, but under protest! I know I've probably lost any leverage I had, but I'd love to find a way to get some kind of credit...
-Dale H."

I'd have pushed the issue originally, but it may be too late now. (Can't hurt to try though.)

A follow-up from a reader that had reported an out-of-warranty leak here back in Oct. 10th:

(added 11/21/2007 - from 11/16 mail)
"Mike, Well, it took a while (Sep 28 to Nov 15), but we are back in business.
We got our dual G5 back yesterday and it is running well. Apple issued an exception code so the repair cost was covered as if it were warranty service. More on my weblog: http://wrecking.org/cbd/2007/11/16/mac-back/
best, Bradley D. "

(added 11/21/2007 - from 11/16 mail)
"bought my G5 Duo core 2.3ghz with 4GB of RAM powermac nov 2004 and on the 18th of august 2007 it shut off and stated ticking... I tried to restart which didn't work. So I called mac support. I opened the side panel and noticed liquid on the rear bottom "foot" I originally thought someone spilled a sugary drink... but it didn't seem right. Anyway the Apple tech couldn't help me and when I mentioned liquid he started asking a range of dumb questions - telling him I had a G5 quad core sitting next to the duo core he stopped asking and told me to go to the mac store to hand in my G5.

I did and it took the about 10 days to repair - under warranty.
Items replaced: logic board, mulit processor dual 2.5ghz (instead of 2.3!), power supply, rear exhaust fan, power supply cover, hardware repair level 2.
regards, Nicolaas "

(added 11/21/2007 - from 11/3 mail)
"Just had the same problem here. I have a G5 Dual 2.7Ghz. Was used for less than 100 hours before the problem occurred, not impressed. The repair centre have looked at it but quoted very high to repair, as out of warranty.

I'm going to contact Apple direct and see if we can get anything sort. Glad to see its not just mine though.
Sean G. "

(added 11/21/2007 - from 10/23 mail)
"Saw your article and just wanted to contribute. I sadly also have 2.7GHz G5 with the coolant leak - suddenly the system froze and I restarted ... nothing happened except for the coolers spinning faster and faster, until I unplugged the thing - then the computer rested for a few days, and then worked, for a few minutes and then it froze again. Tomorrow I am calling apple Denmark, but they will probably not do anything about it. I have read their disclaimers and it surely doesn't look too good...
-Johan "

I wrote Johan to ask if there's any resolution on this.

(added 10/16/2007)
"Just another report of a dual 2.5 G5 coolant leak for a client of mine. Spent 20 minutes on the phone with Apple customer service... no warranty exception for them. Out of luck....
-Philip "

(added 10/15/2007)
"Dual 2.7, from July 2005. Sent for repair/diagnostic for not booting in June 2007. AASP called reporting coolant leak had damaged system PSU, and probably MLB and Processors. No Applecare, ouch, and to costly to repair. I called Apple Support, and got the "I'm sorry for your loss" line and "there's nothing we can do". I asked to speak to Customer Relations and told them I thought a $3k computer should last longer than 2 years, regardless of Applecare, and that there were several Internet articles about coolant leaks and the systems having a "design flaw" in the LCS. I was transferred to an engineer that requested pics of the damage and they would consider a repair. I sent in the pics (see attached) and they authorized a repair. I talked to my AASP , they had me bring in the system and generated a parts list, then called Apple and told them it'd be cheaper to replace the unit. Apple called me back and asked where I'd like a 2.66 Mac Pro shipped to. A few days of legal paperwork and having my AASP send them shipping confirmation for returning the old system and they shipped the Mac Pro.
Phil "

Some other readers also noted they were getting a new Mac Pro system (due to repair parts issues usually). I just wish everyone that had a leak was so lucky. (Although several readers with out-of-warranty leaks initially were told leaks were not covered, sometimes repeated contacts/requests paid off.)

(added 10/15/2007)
My G5 dual 2.5GHz started leaking after 2.5 years and quit working. It's under warranty, 46 days left (close call).
-Mike M."

Ideas for a Leak Warning Alarm:

(added 10/12/2007)
"Excellent website! I too have a Dual 2.7, but so far (knock on wood) no coolant issues.
I do have the revving fans (10-20¡ hotter CPU B) which only go away when I put the processor performance setting to reduced.

Anyway, I was giving this issue some thought as to how to protect against potential future coolant leaks. Though not fool proof, I think one could use one of those cheap $20 water alarms available at Home Depot. (Due to our house having PB plastic pipe (infamous for leaks, especially at crimp joints) I bought several of these at Lowes (Glentronics Watchdog Water Alarm model BWD-HWA for just over $12 each - cigarette pack size device w/9V battery and two metal contacts on the bottom). Here's a different model with multiple remote sensors-Mike)

By simply soldering wires leads to the metal sensor contacts and taping/gluing the other ends (close but not touching) to a small strip of thin (and absorbent) paper inside the case, this might work as some sort of early warning system.
I'm thinking it would take a very small amount of coolant to soak the paper and complete the circuit.
I have yet to try it myself, but I thought I'd pass it on.
Regards, Mike S.
SHIRKcommunications
www.shirkcom.com"

An early warning of a leak could help prevent damage to the Power Supply and logic board. (One reader's photos of his extensive damage showed an incredible amount of rust on the Power Supply (indicating the leak must have been present for a long time), as well as damage to the logic board.) Placement would be key, as he mentioned there was an absorbant mat but not in the area where the coolant leaked from the pump (gasket failure).
If any reader with a LCS G5 tower has done a mod like this (or does in the future) let me know.

(added 10/11/2007)
"Hi and greetings from the UK.... I have custody of a friends Quad G5 which has overheated and at least one of the CPU cores is dead. Apparently the Quad had been 'really noisy' for some time - he presumed it was normal. He called me to ask if the constant crashes were normal (I could hear the fans down the phone, which is what prompted the current investigation.) My friend is a record producer not a computer tech and he just wants to get on with his music, so he bought a Mac Pro and I spent the weekend transferring, UB-upgrading and authorizing his app's. Interestingly, though probably unrelated, his 2nd internal drive - where all his audio files were - was showing SMART status 'failing'. Managed to transfer everything with just one damaged file, luckily - extremely luckily - not an irreplaceable file. (Yes, we have no back-up!)

The Apple-authorized Service Centre diagnosed the fault as a motherboard and/or cooling system fault.
All in all the Quad has been a catalogue of disasters!
The Quad's out of warranty and the repair bill is £799 ($1600) for a complete CPU and cooling assembly, which is obviously out of the question.
I really think Apple should fix this for free, and that is what I'm currently pursuing on his behalf.
Best regards, Andrew R. "

(added 10/11/2007)
"Saw your post after being outraged by this LEAK! Happened to me last friday- computer froze up and went down. Just returned from the "genius" bar only for them to tell me the sad news that my cooling system BURST! Destroying my processor, motherboard and power supply! In other words "Use it as a table".
(for posts can you please include details requested?

* what model of tower (there were several series - what was the clock speed? AGP slot graphics/PCI-X slots or the later PCI-e slot model?)
* when was it bought?
* how long was it used before the leak was noticed?

I am in shock that Apple is not standing behind these machines in ANY way. I have been a Mac user since 1984 and ALL my other units are still alive and kicking butt!!!!!
How far have you gotten with anyone being heard from Apple.. or getting any help or support?
(Did you read all the reports on the page here? Some (but not all) had their systems repaired but often it seems parts for the delphi LCS may be hard to get (the later models had Panasonic LCS - see past posts/pix here) - and some (a few) noted they got replacement mac pro systems due to the repair parts not being available.-Mike)

Ok... Lemme try and answer some of your questions here-

G5 dual 2.5GHz, bought in July of 2004.
I used it everyday since I turned it on. I am a graphic artist and photographer so I am usually in Photoshop everyday...working at hi speed hi volume. So it was used for 3 years - funny my old G4 is STILL kicking!!!!!
Yes I read through ALL the reports and am not done with this issue yet. I plan on working my way to the top before I give up. I can't afford a new machine at this time and this is my ONLY source of income!!! A bit scary.
-Sooz "

(added 10/10/2007 - Also see his later follow-up)
"We've got a dual G5 purchased on August 4, 2004. It's been a problem. We've had it repaired twice under AppleCare (logic board, then logic board plus CPU). Now we have a coolant leak; the machine is dead, with a bad power supply and CPU module. My Apple repair folks suspect the leaking coolant shorted out the power supply...
Not sure what's going to come of this, but boy would I love a discounted MacPro...
(I asked if his system had the Delphi LCS or Panasonic LCS (the latter used in some later models - see photos below)-Mike)
I'm not sure. My guess is the Delphi since I got a very early one off the line. Its last repair was May 2005, and I didn't have time to take it apart before I gave it to my AASP. I'm calling Apple today; if they don't play I'll find out Delphi or Panasonic and go from there.
(he later wrote)
On the hold with Apple now.... wish me luck!
-Bradley D. "

A luckly few here noted they got a (no charge) replacement Mac Pro system (due to delays/problems getting repair parts for the LCS (Delphi LCS I suspect, not the Panasonic LCS). I had another mail today on a leak but the owner sent no info on the model so I wrote to ask for that. (Please include info on the G5 tower model, when it was bought/how long it was used before the leak developed. Thanks.)

(added 10/4/2007)
"Add 2 more G5 2.5GHz towers with coolant leaks. 100% failure rate for me.
Apple still not taking responsibility or offering help.
(Just for the record I asked him for more details on the systems (when bought, how long before leak appeared, etc. - and I assume they had Delphi LCS - see below for info/pix on Panasonic (used in later models) vs Delphi LCS).-Mike)
Both were bought in the second half of 2005. I dont immediately find the exact dates.

I'm not sure when they first started to leak. Certainly it was long before now, you can see the evidence at http://rknochenmuss.ch/G5leak/G5.html
(Includes photos down the page of severe corrosion (check out that rusty Pwr Supply case), pump leaks (gasket failure), notes the absorber mat wasn't where it would catch leaks, etc. From the looks of that PS, the leak must have been present for months.-Mike)

I also heard that some people are getting replacement systems here in Switzerland. Im planning on trying again with Apple tomorrow.
-Richard"

I wish I knew why some owners have gotten repairs covered (out of warranty) or a new Mac Pro system (due to repair parts not available usually) and others not. I'd try again as some have initially had no luck.

(added 10/2/2007 - updated again)
"I have a dual 2.5 purchased probably early 2005 (From the buy date I'm assuming a "Late 2004 series" (AGP/PCI-X slots).-Mike), and it's finally sprung a slow leak. At first I thought a fan was faulty or something as overheating caused the G5 to put itself to sleep, but monitoring programs didn't show any of them running significantly underspeed, so I took it to the apple store where one of the guys found rust on the power supply (only visible through the rear grill).
I've unplugged the computer before it destroys itself completely and am trying to decide whether it's worth tying my primary computer up with a possibly lengthy repair (I keep hearing about a lack of replacement parts) or replacing the thing completely.

This is the second time the computer's had major problems. The first was when the software RAID failed and I lost all of the data on my drives. And now it's finally gone and self-destructed, apparently for good.
I'll be spending today hounding applecare to try to salvage what I can. But luckily none of the important things like the hard drives appear to be affected, so it's just a matter of getting those into external cases and living off my laptop until repairs or a replacement can be secured.

(He later wrote that like some others reported here, he's getting a new replacement system (Mac Pro))
Okay, just an update, after a talk with Apple's Customer Support, they told me that apple would be sending a replacement for free + the price of any upgrades to the model that they provide.

Basically I explained that after getting the diagnosis done at the apple store, I did some research into the liquid cooling system and found that the problem is becoming more and more common. The girl said she'd see what options would be available, and the next thing she said when she came back was that I would get a replacement unit.

So my 2.5GHz dual will be replaced by the 2.66 quad core Mac Pro with the same quantity RAM and HD space that was originally installed. Although I then had them upgrade some stuff, so that'll cost me some money, but $600 is much better than the $2200 estimate, and definitely better than the full $3576 for the machine I will be getting.
-Keith I."

(added 9/26/2007)
"I also had a leak. Bought my Powermac G5 dual 2.5ghz in November 2004 in Greece. Leaked 15 months later. No luck with Apple fixing it since it was past the warranty when it happened.
Cost to fix 1100 euros for a fifteen month old professional machine of more than 3500 euros!
Serial number: CK443H6158K
Has there been any success in getting Apple to fix or replace faulty macs?
-Alex D."

Several readers have (see earlier reports below - some note getting repairs done out of warranty at no cost - but YMMV), but I don't know of anyone that's gotten a refund after they paid for a repair.

(added 9/26/2007)
"Hi Mike! Don't see my G5 leak report on your webpage! You and I went back and forth with this issue months back (April I think). (I remember several leak reports at times over the years, but lately there's been a lot of them - I suspect the Delta LCS (IMHO) is more likely to leak after some age.-Mike)
There are more and more of this machines leaking and it is design flow (you mean flaw?) regarding of someone's intent to downplay it as such. There is website collecting data on all of the machines with this issue... I think you should inform your loyal readers about it:
APPLE PowerMac G5 Coolant Leaks World database
http://www.fusina.net/G5_coolant_leaks/index.php?lg=uk
-Dinko M. "

(added 9/24/2007)
"I work at a Mac shop. We had a guy bring in a G5 with a coolant leak about a month ago. We ordered the part, but waited...and waited...and waited. Apparently, it was backordered all the way to hell. Apple told us on at least one occasion that it would ship on a certain date, but never did. This G5 is out of warranty, yet today we learned that Apple will be flat-out replacing this G5 with a new Mac Pro, no charge! Something tells me that Apple can't get the parts they need anymore and is trying to get failing G5 coolers/CPUs out of the channel while keeping customers happy.
-Noble "

Some other readers also noted long delays in getting repair parts, with some getting a Mac Pro replacement system vs repairing the G5 tower. (FYI - I've updated an earlier report from Havard to note they now have a 4th leaking system (out of 8 total).

(added 9/21/2007)
Hi Mike, I thought I'd note on the recent discussion about the LCS in some PowerMac G5s. So far and from what I've seen (Technician at an Apple Retailer), it looks as if the Panasonic-based cooling systems aren't leaking. All PowerMacs we had to throw away have had Delphi-based cooling systems. (Delphi does seem a common factor. As mentioned before there were 2 sources for the LCS and IIRC some had dual pumps, others single. See below for pix of the 2 systems from the April 2005 xlr8yourmac.com news page.-Mike) Most often, the power supply was destroyed by leaking coolant. Replacing this is not really helping in many ways - with two machines, the logicboard was dead too. Besides, the question is to what amount the coolant would continue to leak. (Of course with any leak, the #1 priority is to fix the source of the leak, not just other components damaged by leaking coolant.)

Although the main leak seems to be coming from the pump, the delphi-based systems (all that I have seen so far, even if not yet dead) also leak at the junction to the copper/metal plate that touches the processors die. The panasonic systems I have seen have always been 100% clean from any coolant, but there are far more delphi systems out there...

PowerMac G5 with cooling leaks started to come in only a few months ago, before we could not see this failure besides some rare cases.
best regards,
Mike S.
Technik Niederbipp "

Pix of Panasonic LCS System (vs Delphi LCS):
I'd forgotten about this past posting but James sent a reminder the April 15th, 2005 news page here had photos of his Panasonic LCS system (he had just bought a Dual 2.5GHz model). He sent 2 photos (click for larger versions) that look different than the (Delphi) LCS in earlier liquid cooled models. Photos of the original (Delphi) LCS are here

There's some internal/more detailed pix from a dual pump LCS from a Quad G5 (Panasonic LCS I think) at this .mac photo gallery.

FYI: I've updated Adream's earlier report with his latest email noting that Apple UK covered the repair (out of warranty) and he has the G5 tower back now.

(added 9/20/2007 - updated 9/24/2007)
"Hello Mike... We have 8 liquid cooled G5s.
So far 3 have had coolant leaks: (now 4 - see below)

1) G5 Dual 2.5GHz:
Production year: 2005
Production week: 06 (February)

Died May 2007. Heavy black smoke triggered in the middle of the night. Bad smell in entire office. Repaired outside warranty by apple. Took 5 weeks for replacement parts, CPU, PSU, Motherboard. Has been OK since repair.

2) G5 Dual 2.5GHz:
Production year: 2005
Production week: 08 (February)

Died June 2007. Leak and black smoke. It was in use, so we could unplug it immediately. Repaired by Apple, but just died within days after returning to us. Sent back to Apple for new repair. There is an expected 1-2 months delivery time for parts. Still waiting

3) G5 Dual 2.5GHz:
Production year: 2004
Production week: 51 (December)

Died June 2007. Just leak. No smoke. Was repaired free of charge. Had several kernel panics when it returned. Didn't bother to check much about why, just sent back for new repair. There is an expected 1-2 months delivery time for parts. Still waiting.

(Update - On Sept. 24th he wrote)
I mistakently counted our (air-cooled) 2.3GHz models in the total, so luckily we have only 8 liquid-cooled macs, not "around 20". (Number corrected above)
However I found another one leaking, so we now have a 50% failure rate, 4 leaking out of 8.

4) G5 dual 2.7GHz
Production year: 2005
Production week: 19 (May)

This has probably been leaking slowly for some time. There are dry dark muddy crystals on the metal plate in the bottom, coming from under the CPU. The mac is still working without any noticable problems. Since it will take forever to get replacement parts I am probably using it until it melts...

Production year and date is based on serialnumber +
http://www.chipmunk.nl/klantenservice/applemodel.html
-Havard "

Thanks for the detailed info.

(added 9/20/2007)
"Hi all, My 19 month old G5 Dual 2.7GHz has now blown itself to bits with the coolant leak. The cost of the system new was R24,000 and the repair cost is R18,000. The response from Apple is ZERO. As we cannot get extended AppleCare in SA apparently we must not expect our "Quality" Apple products to last any longer than the warrenty. Let the buyer beware.
-Chris C. "

I'd try another Apple contact - some (but not all) have reported they've gotten leaks repaired out of warranty.

(added 9/19/2007)
"Just to add to your list of coolant leak reports..
2.7 GHz Dual Power Mac G5. Used for 2 years, 4 months (28 months) before leak was first spotted during routine check-up. Under Applecare warranty (whew!) Apple replaced the machine with a stock Mac Pro (2.66 GHz Intel) after 19 days in the shop - couldn't secure all the repair parts after 19 days, thus the replacement offer from the Apple Store manager. I got a new machine, so I'm happy with Apple's response.

I spotted the leak BEFORE the Mac started acting funny, so I strongly recommend a monthly check of the Mac's interior (focus on the back-bottom end near the power plug connection) even if your Mac seems to be running OK.
-Nelson"

(added 9/13/2007)
"Howdy Mike, Naturally I became concerned after having read all the reports (on the Xlr8yourmac.com front page of course!) of coolant leaks on the final revision dual G5 Powermacs, so I proceeded to open mine up for an inspection--I actually had been meaning to blow out all the built- up dust with compressed air anyhow. Sure, mine is the dual 2.3GHz G5 (PCI-e model "late 2005" series), and not one of the dual 2.5GHz or dual 2.7GHz versions, but upon opening up the side panel, I noticed silkscreened onto the powersupply cover was something along the lines of "check for leaking coolant blah blah etc.". "WTF?!?!", I spoke aloud to myself, as I was under the impression that mine was in fact air cooled and NOT liquid cooled.

So, off with the other shrouding bits and pieces, and lo and behold, there stood a traditional heatpiped air cooled heatsink setup... so why the warning on the powersupply? Oh yeah, mine was a refurbed unit, so the whole parts-is-pieces mix-and-match idea came to mind.

So, I believe it is safe to assume that the dual 2.3GHz units do NOT have liquid cooling in them despite the fact that they apparently have the same warning silkscreened onto the top of the powersupply.

Once again, to reiterate, this is from a refurbished late-2005 spec (although I purchased it about a year ago from the Apple Store with a 3-year Applecare extension like a smart person would do) dual 2.3GHz G5 Powermac, PCI-Express, and for sure the heatsink is an air cooled unit (copper heatpipes with aluminum fins) without a hint anywhere of any fluid pumps. So basically, if I see liquid, then one of the kids has some serious explaining to do!
-Leo P."

Here's some links from the FAQ's Apple G5 section (which has links to all the Apple specs pages for the 5 series of G5 Towers from 2003 to 2005) - the PowerMac G5 (Late 2005) (Dual Core/PCI-Express slots) doesn't mention which have LCS (Liquid Cooling System), although I assumed all the dual-core models did (apparently not for the dual 2.3GHz per Leo's comments). I checked the late 2005 G5 Developer Docs but they don't mention LCS either. The Apple specs doc on the "Early 2005" series (last of the AGP slot/PCI-X slot G5 towers) lists "LCS Heatsink" on the dual 2.7GHz model but apparently some "Late 2004 series" also had LCS based on leak reports here.

(added 9/12/2007)
"Yes, I have had a coolant leak. I think it was the end of July/early september. (2007?) I have a G5 2.5 DP with 1.5 gig of ram, os 10.4 with X800 G5 video card. One day, the machine wouldn't turn on. Fans may have run a little wildy, but gave no indication of trouble until then. Took the machine to my local Apple place. They told me it was the power supply and would be fixed in a week. Then at the end of the week, they told me that the cooling system had sprung a leak and they wouldn't know how long it would take to fix (the words "nearly forever to get parts" were spoken). I hit the floor. I called appleCare and told them of my situation, how I had to use my mom's old G3 Pismo for Internet use, etc, etc. They connected me with a Product Specialist. My machine was fixed the week after that.
What got fixed:logic board, CPU's, Power supply, etc. Total cost to Apple Canada - $2,025. Cost to Me: $0.
This is the second huge failure this machine has had. The first one: logic board went down, taking the video card and hard drive with it. The stuff I had on the hard drive was recovered. Cost to me $80. Cost to Apple - about $1500 plus a technician came to my house to install the video card. Apple's stuff may be generally reliable, but the days of an unbreakable Mac may soon be over.
Moral of the story: Get AppleCare, folks
John B.
Edmonton, Alberta
Canada "

(added 9/12/2007)
"My dual G5 2.7GHz sprung a leak after nearly two years of service. I took it to the Apple Store where they told me they've seen the problem before. With no AppleCare (never needed it in 20 years), I was out of luck. The cost of repairs was within $500 of the price of a new MacPro. After writing a letter to Apple suggesting a "Repair Extension Program," a "representative" of Steve Jobs called to say that while the coolant leaks are a reality, the failure rate is not high enough to warrant a recall.
-Dennis C."

(Updated 9/11/2007 - Updated 9/21 - see added comments)
" my dual 2.7 G5 has just sprung a leak too, luckily I have retired it before it goes bang, but it's out of warranty. It cost £2400 when I bought it 24 months ago and now it's sitting doing nothing. Lets hope there is eventually an extended repair program for these liquid cooled G5s with delphi pumps in them as I am certainly not the only customer that can hardly afford to spend another £2400 so soon after buying this. (It's worth calling Apple about this, as some here have reported they were able to get a repair covered out of warranty, although again YMMV.) All my previous macs have been very reliable, and its heartening to see apple have repair programs for other manufacturing defects (delphi's defect in this case I'd like to add). So add me to the rapidly extending list of G5 cooling leaks/failures. So far I havent heard back from apple but as its out of warranty I'm not expecting too much :-(
I also have of a friend in my town who has also had a coolant failure in his dual 2.5 G5.
(Update: - he later wrote that the repair is getting covered)
update on my leaky dual 2.7 G5
I spoke to applecare UK today who passed me onto an engineer, who agreed to sort it out for me giving me an exception code (as the machine is out of warranty)
so I took it to our local apple repair centre and they said it would be fixed free of charge!
I'll keep you all posted as to the progress but so far so good.
(On Sept. 20th he wrote it's been repaired)
Hi Mike yet another update the G5 came back after 4 days with a new processor and cooling system installed and appears to work fine. All work was done free of charge even with the machine over a year out of warranty. Apple UK have really come through for me in this case
thanks again for your continued work helping to make the mac community a community!
Regards, Adream "

" My Dual 2.5 G5 leaked coolant within the first year. I did have AppleCare. Apple sent a technician to my house, he confirmed the leak and ordered a bunch of parts. He came back a week later with the parts, and upon further disassembly realized that the coolant had caused considerable corrosion in the case under the power supply. He called Apple and got authorization for a new Mac. I picked up a brand new Dual 2.7 G5 that weekend at the Apple Store--they even swapped over my SATA PCI-X card, Gigabit Ethernet PCI-X card, memory, and hard drives. Bottom line: things break sometimes. I suspect a faulty design in the Delphi cooling system. Apple did the right thing immediately with no argument (they did ask if I was sure I hadn't spilled anything on it!). Happy customer. Only thing Apple could have done better is a little quicker turnaround.
-Scott W."

Reader Repairs a Leaking Pump:

"Mike; For what it's worth on this g5 leaking coolant business....here's my experience.
I picked up a used G5 2.7 very cheap a month ago. It had leaked coolant and fried the power supply. There was corrosion all around the power supply and no sign of life of course, but the logic board actually still looked ok to me, so I thought what the hell. There was also a fair bit of sooty crap on the case, on the MB near the CPU's due to the power supply frying but nothing that looked like the board had actually been damaged. So I thought I'd just pull things apart to see exactly where the leak had occurred.... Figured i hadn't spent much, didn't have much to lose. NOTE: to remove the CPU's, you will need the usual collection of Torx screwdrivers, but you also need a LONG extension driver, maybe 5 inches extra length, to get at some torx screws which attach the heatsink/CPU assembly to the motherboard.

After removing the large CPU/LC assembly from the motherboard, I could see there was no leak from the cooling hoses themselves, they were just fine, ( they are made of VERY tough braided material.) But a leak had obviously occurred somewhere, and there were crystals around the junction of the hoses with the actual CPU blocks, as others have noted. Plus there a little coolant residue right behind the coolant pump itself, right where it was mounted to the CPU aluminum block. This looked like the most likely site of failure. However, I discovered that simply removing the pump from the hoses was pretty well impossible...they are so tough and rigid, I figured I'd just wreck something trying to yank them off.

So I figured I'd just leave the whole CPU/ Heatsink assembly intact, and try to unscrew the pump from the rear. I had to remove some screws from the big mounting plate, but this was not difficult...just be relaxed and methodical if you decide to try this. I had to cut one of the coolant hoses off the pump too, so I could rotate the pump and get a decent look at how it was constructed. (Any decent PC supply store has replacement hoses, coolant, clamps etc...I used vinyl tubing and tiny ring clamps from my local automotive store. ) As soon as I cut the hose a bit of coolant leaked out of course, but a small rag quickly mopped this up.

Once I saw how the pump was constructed, I realized why it had probably leaked. It consists of three simple moulded plastic "layers", (A front, middle and back) simply screwed together as a sandwich, with 2 simple rubber O-rings forming a seal between the layers. There's no gasket material or other sealant, just these 2 soft rubber O-rings. In the front, where the inlet & outlets are located, there's a tiny inset wheel with little scooped impellers. This wheel does all the work. (Electricity drives the wheel, which simply moves coolant like a tiny old-fashioned water wheel, through the hoses, over the CPU's, past the the radiator etc., round and round. It's really pretty basic!) This little wheel looked just fine, turned freely etc. I wondered what the back & middle sections were for. The back section had a round rubber diaphragm thing, mounted on 4 small springs...it took me a few minutes to realize it had to be some sort of basic expansion device, to account for the changes in coolant volume as the computer was being used, got hot, cooled down etc. Sure enough, there was a tiny hole in the middle piece of plastic, to allow coolant to enter this tiny expansion chamber. However, it was also pretty clear the O ring had not been sufficient, and coolant had simply forced its way past it, and oozed between the plastic layers, onto the cover of the power supply, then down into the electrics etc.

So I then cut the other hose off the pump (there's only 2 attached to the pump, in and out), which separated the pump from the rest of the cooling assembly. I disassembled the pump and put it out in the sun to completely dry. There's only 7 or 8 components to it, it's really basic, as I said before. I then got some high heat silicone sealant ( local hardware/ automotive store ) smeared it on the mating faces of the pump, re-installed the O-rings and put everything back together. I then actually had to cut the Delphi hoses right off the aluminum pipes with an Olfa knife ....as I said there are very tough, and were impossible to pull off, even after heating with a hairdryer) Some short sections of clear vinyl tubing completed the repair. (it's FAR more flexible, and it needs to be, because the DELPHI hoses are really overkill, and there's very little room for movement all around. The ends of the aluminum pipes of the cooling system are also very close to each other, so it's tricky to get enough room to slide the hoses over these aluminum ends. I then let everything sit for 2 full days, to allow the silicone to cure and bond properly.

Of course what we're talking about here is a "closed loop" cooling system, so there should be no air in the hoses, coolant only. As I mentioned , the little expansion chamber works in lieu of a regular expansion tank, such as you'd find on a car. But still, there must be room for expansion, or something will blow. So after the silicone had cured 2 days, I had to somehow get the hoses - and more importantly the pump - full of coolant again, prior to giving the thing a test run. An inkjet syringe did this job nicely, slowly filling the system via an unconnected hose till it was full. I got the coolant from a local PC supply store...any store catering to overclockers will have loads of it. I kind of forced the coolant through with the syringe, to make sure there were no pockets of air hiding in nooks and crannies. I noticed a few tiny globs of residue come out at one point, which made me wonder if an annual backflush of a system such as this might be good policy, and if some precipitate had formed somewhere and perhaps blocked the pump, or some such thing, which then resulted in excess pressure blowing coolant right past the o-rings etc. Personally, I still think the O-rings, standing alone without any other gasket/sealant material, are the weak link in this system, and were the reason this particular G5 became a casualty.

But to continue my little saga... At this point I still didn't have a working computer to give the cooling system a trial run on, so i gambled and ordered a new power supply. I figured i'd just re-sell the P.S. if things didn't work, but by this point I was really curious to see if the pump would actually work after my surgery, if the CPU's were still good, the logic board ok etc., just what the machine might be worth, even if it was just for parts. Anyways, long story short, I installed the power supply, attached a monitor, plugged it in, crossed my fingers, pushed the power button. Apple chime. The damn thing worked! Been running 24/7 for 3 weeks now , runs like a train.
So other readers might be interested in this info...I'm betting a great many of these G5 failures are due to coolant getting past these damn O-rings on the little delhi pump. The rest of the liguid cooling system looked pretty bullet-proof to me. It's very solidly made. My advice? Every couple of years, G5 Liguid Cooled owners should think about putting put some rainy afternoon aside for preventive maintenance. Get organized.. get a short length of vinyl tubing and a couple of tiny ring clamps. Carefully cut one of the lower hoses right off and flush the coolant out. Dispose of the old coolant responsibly, somewhere a kid or animal can't get at it...it's lethal when ingested, pretty harmless otherwise. (FYI - See Material Safety Data Sheet on Coolant.-Mike.) There's a screw cap on top of radiator itself, where you can refill, add coolant etc. Replace the hose you cut off off with the vinyl hose/ ring clamps, and use the inkjet syringe method to refill the system. An ounce of prevention, as they say! And if you've got a G5 that has just started leaking, I would definitely get some silicone sealant and and try to repair the pump, right off the bat. Repair shops probably tend to err on the side of caution when they see these G5 casualties roll in...they look pretty corroded and burnt up, and the tendency is probably to write the whole machine off. But as in my case, they MIGHT not be so bad after all. A couple of hours with some screwdrivers, vinyl hose and clamps, and you just might be up and running again!
Hope this helps someone out there.
Cheers, Dave "

"I've just got my Powermac back from the service centre, it's a dual 2.7ghz model which I got in June 2005. Luckily it was my first machine with AppleCare. I leave my computer on all the time because one of it's uses is as a PVR. I had no prior warning before it gave out, and having a cursory look inside thought it was a blown power supply. Like your other readers, I was informed by the service centre it was the coolant and after not hearing for them for 10 days, they told me they had to replace 6 parts and were waiting on some parts. They asked Apple to replace the whole unit, but they refused - They even had to replace the case!
It ended up taking a month for them to fix it.
regards, Michael F. "

"Earlier this month a coolant leak caused my Dual 2.5GHz G5 to die.
To recap: the computer became wonky, wildly spinning up fans at the slightest provocation for a couple of days, passed hardware test suite, then became unbootable; upon moving the box for a look see, clear coolant ran out of the case. I called AppleCare, explained all the details, and luckily got the right person, because he authorized a repair right off the bat (the system was way out of warranty, being nearly 3 years old, but I didn't have to make a peep).

He made an appointment for me at my local Apple store for later the same day, and I dropped the box off. Whatever came up on the screen at the Genius counter when they pulled up my AppleCare ticket definitely raised some eyebrows (the Genii all clustered around the screen to get a peek)...

Now three weeks later, I just got my system back and it seems to be working fine. Apple replaced the logic board (twice!), the dual CPU board, the power supply, and the entire external case (it came back covered in plastic!). My bill: $0.
So, there _is_ hope for those with this problem...
(he later wrote)
As further follow up, the system seems to be running normally, although the fan behavior is not quite the same as it used to be (spinups seem more frequent -- I wonder if the new mobo has different firmware?). I plan to rebuild my system disk anew, from scratch, and then do a little temperature monitoring (I've never bothered before, since the system is stock, with exception of some extra RAM, and I seldom push it hard). I need to work it to see if anything shows up before my 90 day warranty expires.
Regards, Miles"

"I have a G5 powermac SN#(omitted here) that has leaked coolant and wanted to let you know about it. I am an IT tech at a school district and thought at first it was the power supply as I have it on 24/7 and have had it a few years. So I took it apart and removed the power supply and brought it to an apple service provider where an old co-worker of mine now currently works so I could get a hookup on the part from GSX since I can't order it here at the school myself legally. Anyway, he informed me that the water like material on the bottom of the power supply I thought might have came from (blown) capacitors was likely from liquid damage. I went home and checked the processor heatsink and sure enough it had leaked. I was pissed.

I called apple the next day and after an hour on the phone with them and raising it 3 tiers I was told that the repair would be covered despite my lack of getting applecare. So I brought in all the parts to PowerMacPac here and am having them replace the logic board, processors, case, heatsink, and power supply. I might even get a new Mac Pro which I have argued with them several times as I need to get my machine up and running and my hookup at PowerMacPac said it was going to be until October until the case came in.
The Apple rep had to put in a request to get the case in from a local service provider quickly. The case came in and now I'm just waiting for the processors.... I've expressed my worry of this happening again in the future multiple times with the apple rep helping me. He says that usually after this is fixed the problem doesn't occur again. I have read several articles that say the Delphi radiators they used are prone to this problem. Maybe I'll still get a new mac. I'll know soon enough and have certainly been trying and arguing to get one.
Either way even though this is a total pain I am still impressed with apple's custom service and willingness to help me get this taken care of. The rep gave me a direct line to contact him and his email so I don't have to jump through a bunch of hoops and wait on hold everytime I want to contact him.
-Erik"

" I am looking at a coolant leak. First the power supply was sparking, so I got a power supply to replace it. The service center took it apart and then they told me that it was heatsink and coolant leak that needed replacing. (When was it repaired? How long since the repair did it leak again? (wondering if there's some sort of warranty period on repairs)-Mike) It is a dual 2.5Ghz. Been in use since 2004. The apple care just expired on it, 2 months ago, so it can't be fixed by apple care. (a few readers with leaks outside the warranty somehow got the leaks repaired at no cost (see below), although that is not the norm I suspect. One of the reports below includes info on a company that did the repairs at a discount (compared to apple estimate/cost) also.)

This is a school computer and the unfortunate thing is that we are in Kenya. So it's very very hard to get parts. For them to get one, it has to be ordered from Europe and could take about 8 weeks. I don't know what to do. I was away on vacation. When I got back in early August, I plugged it in to get it ready for school, but it started sparking.
So that's where we stand right now...
Cheers, Elvin "

It can't hurt to contact apple and see if they would cover it - especially since it was previously repaired for the same problem (and used in a school). Worth a try.

(updated with a follow-up)
" I am glad you are collecting data on the G5 Liquid Coolant failures. Even though the supplier of the Coolant Part has since gone bankrupt Apple has the responsibility to their customers. (I think he's talking about Delphi, but IIRC there's more than one source and some models had single pumps, others dual pumps.-Mike) Apple should have issued a recall of the product when they became aware how widespread the failures were. Is APPLE turning into THE BAD APPLE?
Purchased when it first came on the market my G5 2.5 Ghz dual processor leaked the coolant out the bottom of the unit on July 17, 2007. Since that date it has been held up in Apple Service awaiting replacement of the processor. After it finally did arrive on August 8, the service informed me that even after replacing the Processor, Logic Board and the Power Supply the unit still failed to work.

The first failure had occurred back on April 17, 2007 with a catastrophic unexplainable Hard Drive failure, which wiped out two years of my life as a Graphic Designer and Artist. (ALWAYS have a backup of your important files (with any system). The cost of a firewire drive for backup is relatively small and is priceless when a problem like that happens. (The internal DVD burner can be used for backups also of course, although tedious if you have a huge amount of data to backup.) Sooner or later, anything will fail (and drives can also get corrupted from other causes). Especially when you have important/valuable files for a business, the first purchase you should make is a backup drive if you don't already have one. I'd highly recommend one even for home users to backup user files that can't be replaced by reinstalling an OS, etc. A clone of a boot drive (completely) is also very handy to have in case of OS X or other Update problems.-Mike)

Essentially both my business and show schedule had to be put on hold.
I have spent countless hours trying to get action from Apple, the last lead looked promising, but again led nowhere so far. I am entitled for a replacement under Apple Care Warranty.
I have suffered enough damage and will do whatever it takes to hold APPLE accountable.
(later in the day he wrote)
I just got my faith in Apple restored... The last woman I had been talking to at customer relations did follow through and I will be issued a replacement. I will let you know when it does happen. I am very relieved, I have been an Apple customer since the very first Mac came out, going through all the upgrades and as you know, we do love the machines.
Best regards, Jutta S. "

I bought one of the first Macintosh 128K's in 1984 (doesn't seem like it was that long ago) and dozens of Macs since then including a few PowerComputing models, a Umax S900, built a couple Genesis machines from parts.

" I purchased a PowerMac G5 Dual 2.5GHZ around August 2004, the service contract expired on 8/17/2007- I am now sitting on pins and needles.
Had a coolant leak 8/12/06. According to the Apple Care Report, Apple replaced the:

• Logic board
• Multiprocessor, Dual 2.5 GHZ, w/LCS
• Power Supply, 600W, Grommet
• Hardware Repair-Level, 2

Cost: $1789.69
Took 3 weeks to get it all done - they would only do one thing at a time.
I've been checking the inside for leaks once a month ever since this happened - very nervous!
-Larry "

I was surprised to see that several readers have mentioned they were able to get repairs done in some cases out of warranty, although YMMV and I'd not consider it a sure thing.

" I had a G5 Dual 2.5 that leaked coolant that was less than a year old (still under warranty) and had a independent Apple dealer look at it. I used it for home office and it was on about 14-16 hours a day. Took to long to get parts, so I complained to Apple. They replaced it with a new Quad G5 2.5. Had to eat the ram, but it was worth it. Purchased Apple care with new unit. Definitely a common problem with liquid-cooled Duals. Get (Applecare) warranty!
-Phil R. "

" I have had two machines of five that have started to leak. We didn't see that the machines were leaking before it was to late. I don't know how old they were, but the warranty time had expired. It was two weeks between the machines crashed and I reported the machines to Apple one at a time. One of the machines Apple replaced with a new Intel machine and the other one they repaired for free. They replaced a lot of parts in the machine that were repaired.
Kind regards,
PŠr-Anders
Sweden "

" Dual 2.5 G5, purchased Nov 2004, fried power supply, motherboard, both processors in March 2006 (16 months).
I got the green dripping liquid, sparking, smoke and then all was dead.
Apple store cut $1000 off of the repair due to the fact that it wasn't long after the standard 1 year warranty had expired (and I buy a lot of Macs).

This was the first Mac I seriously considered buying the Extended Care for (due to a radiator being in my computer!), but didn't. It would have saved me serious cash.

At this rate, I expect the current computer to go bad this fall, just before I get the cash to buy a Mac Pro.
-Tim
Dual G5 2.5
Dual G5 2.0
Powerbook G4 1.5
Powerbook G3 400
Mac Mini 1.68GHz "

My (air cooled) 2003 Dual 2GHz G5 (first shipment) is still running knock on wood. (Replaced the Pwr Supply early on for a noisy fan, but otherwise no problems yet.)

"I had a G5 dual 2.5GHz (bought 22 Oct. 2004) continuously running for about 2 years. In October 2006, suddenly it died.
I had it repaired on my own costs (logic board, CPU, powersupply - A lot of corrosion on the Power Supply). After the repair I sold it and switched to a Xserve Intel.
Regards, Beat"

" G5 dual 2.5GHz, 2 yrs old - out of warranty. Had a problem with fan noise, Apple said caused by coolant leak. Apple refused to repair - gave repair estimate of $1700.00!!! Got it repaired by indep. repair store for $750.00. Took a month to get the parts - probably because so many G5's are leaking, parts hard to come by. Where's the class action?
(I asked what company did the repairs)

DI-NO Computers
2091 E. Colorado Blvd.
Pasadena, CA 91107
626-795-6674
www.di-no.com

Di-No is an old Apple dealer located near Cal Tech in Pasadena. With the Apple Stores in Pasadena & Glendale, they don't really sell Apple hardware anymore -- they mostly do repairs.

Repaired G5 seems to be working fine, but I'm trying to add the G5 to the Apple extended care package I have on my iMac & laptop. I think anyone with a PowerMac G5 should pick up an extended warranty ASAP. The standard Apple repair lines seems to be:
1. If unit still under warranty: The coolant is leaking so the warranty is voided (!?) (which is what they told me when they thought my extended warranty convered the G5; (FYI - others with leaks under warranty said Apple covered it.-Mike) or

2. If the unit is out of warranty: Sorry, no warranty, and coolant leaks are not a typical problem with the G5, so Apple doesn't "help" with the repairs.

At least if you have a warranty, you can go up the customer service chain and find someone to repair or replace the unit.
-Al "

"I have a Dual 2.5 GHz PowerMac, which is 2 Years and 11 Months old. Two weeks ago the mac started acting abnormal (high volume spinning fans and having lookdowns/crashes through out the day). One morning the machine did not start up any more. Switching on brought for half a second the light on (on the front of the G5) and nothing.

My apple certified tech opened it up and discovered green liquid (coolant) and traces of fluid everywhere around the cpus, the cooling system and down to the powersupply which died first from the liquid. I talked to Apple the next day, and had a very inexperienced rep on the line. He did not even know (even given the serial number of the dead machine) that this was liquid cooled machine. He asked if I had put any liquid above or on the computer, because inside the Mac there is no liquid (LOL).

Since I am working as an instructor on film classes I told the rep (who was definitely unwilling to repair it at apple's cost as the machine was far out of warranty) I dropped a hardball and said: "If Apple does not fix this, because this is definitely their fault, I will make a video and put it on youtube..."
Anyway, he said I should take it to an authorized AppleCenter and I did that, the tech called me a day later and said everything is fine. This serial number was already under cleared for repair.

Now I have the machine back and working: They changed 2 CPUs, cooling unit and power supply. The inner case is in some parts now heavy corroded. I will not even imagine the cost to have paid for the repair myself. One last thing: The Apple Rep said next time I should consider getting the extended AppleCare Warranty...
(Since this is a hot thing and I had to do a lot of talking (with Apple reps) I would like to keep my name under wraps, but can only recommend those affected to stay "hard and focused" when talking with Apple Reps on this particular issue :-)
regards and greetings from europe.
(name withheld by request)"

Most companies will not pay for any repairs after the warranty period, unless it's due to a known/common defective component, etc. - although several readers have said they convinced them to repair leak damage after the 1yr warranty had expired. (Apple has posted several Exchange and Repair Extension Programs in the past however, including a Power Mac G5 Repair Extension Program for Power Supply Issues.)

"We had a G5 leak coolant over the summer. It's 2 year old, so that would make it one of the same generations as Zach's. This is the only instance of this type of failure i've seen, and I run 4 labs totaling over 80 computers.
When it began to leak coolant, it apparently got into the power supply, shorted it out, and make a good bit of smoke and noise. I called Apple (we have Applecare), and the specialist asked me health and safety questions from a script about skin contact and the like. (See Material Safety Data Sheet)
Apple repaired the G5 without hesitating, having to replace everything short of the RAM, HD, optical drive and video card. They even had to replace the front switch where you turn it on.
At least for me, this is (so far) an isolated incident.
-Corey
Multimedia Lab Coordinator
University of Tampa "

I'd had some previous reports of leaks (in the news at times and on the G5 random shutdowns page), but his comment on a large number at once made me wonder if others with similar age may start showing the problem also. (Worth checking periodically at least.) Let me know if you spot any others leaking in the future.

"I have 2 of the first generation dual 2.5 GHz G5s. One made an audible bang and smoke came from the case. Unfortunately, this was after the warranty period (no Applecare) and it was too expensive to repair (>$2000). The other has shown no signs of leaks. It's easy to see if you have a leak, just open the case and look for liquid or salt deposits. (Do you mean corrosion?)
No, it looks to me like when the coolant dries it leaves salt deposits.
-Ian "

"Around the beginning of June this year, the unthinkable happened. My beloved 2.5 GHz G5 started making sizzling and popping noises and then it just died. Unplugging it and removing the outer cover revealed that the worst that could happen had happened. I'd been bitten by the dreaded G5 coolant leak. Still, I'd paid for the full Applecare cover and there was still a couple of months remaining so I was sure that Apple would see that the problem was resolved satisfactorily.

My first step was to drop into the retail branch of my local AASP and have a chat with a manager there. He advised me take the incontinent beast to their service centre and the problem would be dealt with. Once I got there (by expensive taxi, incidentally) it was a different story. The tech confirmed the leak and the fact that the machine would not start. He then explained that, as it was very likely that multiple parts would have failed, Apple don't allow them the discretion they would require to replace more than one part and I would have to work through Applecare directly. I phoned Applecare from my mobile, hoping for them to give their OK for the repair to be conducted locally but they were unwilling to deviate from their "1 component' guideline, although they arranged for a tech to phone me within 48 hours. Another expensive taxi later and I was back in my flat and starting to get frustrated.

The tech from the contractor Apple uses actually phoned that afternoon and arranged a pick-up for the next day, which also went as planned. He phoned back a couple of days later to explain that there was a long wait for the processor block, which was on backorder and that he'd also ordered a power supply. It looked like they'd be waiting a minimum of 3 weeks before getting the block and even then, there was no guarantee that there wouldn't be more damage. Now, a week or so to fulfil the terms of an extended (and paid for) warranty is reasonable but I didn't feel that being deprived of my Mac for at least a month was acceptable and I told him so (politely). He suggested I talk to Apple and I said I'd do that.

Before talking to Apple, though, I did a little research on the internet and found that I was by no means alone. Cooling system failures on this model aren't as rare as they could be, especially around the 18 - 24 month mark. Some labs running multiple G5s are reporting 15% - 20% failure rates. I rang Apple and asked for customer relations. I asked about the availability of the processor and was told that they'd expedite delivery to their contractors and that it'd get there within 48 hours. I also asked about the failure rate; what would happen if the new processor failed after 18 months; and whether they'd extend the warranty to a reasonable level. A resounding "NO" was the reply. A standard 90 days from the date of the repair was all they were prepared to offer. Still, at least the part was on it's way and I'd get my machine back soon, eh?

A couple more days down the line and I returned a missed call from customer relations. The original estimate for the processor's availability was correct. Well, I say it was correct. I was told it may well take even longer. However, the rep was much more sympathetic than the previous one and I had the impression that she had a bit more influence. She said she'd see if there were any more options and phone after the weekend. I was thinking of asking for a replacement machine by then. Even an older G5 would have done, as long as it was air-cooled! On the Monday, just before the WWDC keynote, I had another phone call. The delivery date for the processor had been pushed back another week, so she suggested replacing my G5 with a Mac Pro instead of repairing it. I didn't even have to ask. There was a delay as my G5 was at the contractors and my hard drive was with me. Her supervisor had left for the day, but the next day, he said it'd be OK for me to return the hard drive later.

On the 15th June, around 3 weeks "apres le deluge", a brand new 2.66 GHz Mac Pro was delivered. I had some third party RAM and a NVidia 6800GT in my G5, which I kept and sold in order to fund some RAM. The lesson here is to always be courteous and polite. At no stage did I raise my voice, although there were times where I felt I ought! I do wonder, however, how many others are having the same issues and whether Apple is doing anything outside of Applecare, as I believe this to be a design or manufacturing fault.
Regards, Calvin "

(from 8/27/2007 mail)
" I had a G5 Quad 2.5 GHZ that I bought approximately in June of '06 in Sept '06 it sprung a coolant leak and the local Apple store quickly replaced it with a new unit...
("RecordingArts") "

"We actually had two G5s, bought the same day, die the same week because of a coolant leak. They were out of warranty about a month or two and the guys here at work were just going to drop the issue and buy new machines. I suggested we get some satisfaction from Apple on this issue as it was clearly a manufacturing problem. After we spent some time on the phone Apple came through and are repairing both of them. They should both be fixed this week. I hope Apple comes through for others with the same problem.
-Jeremiah D.
Systems Analyst "

"Lots of them can be found on the net - Apple should start an extended warranty program for the liquid cooled machines:
Apple forums thread on G5 Coolant Leaks
Powermac G5 Coolant Leaks
I'm checking my own G5 2.5 almost everyday for liquid inside for the past year. It's a shame, a $1 plastic tub could save all these machines from dying. But you can't look behind the processor cover. It is sealed (later models) and can't be opened without breaking this little plastic seal. So the user gets no chance to see that the machine starts leaking before it's really bad.
When my Apple Care Warranty is over i will break the seal, remove the cover and put a plastic tub below the processors.
(He later wrote)
Mine is november 2004 - 6 months before the 2.7 came out. Mine is running 18 hours a day which is possibly worse because the material the cooling system is made of is getting more stressed by very different temperatures inside the case.
-Mark H. "

Again I'd had several reports on coolant leaks in the past but after Zach's comments on a large batch leaking I thought posting this would be good to see if others may be developing the problem (not just those that had leaks earlier).