Quad G5 Liquid Cooling Pump Chugging, nasty thermal disparity between cpu's

Hi. Thank you for that link. However, I did read somewhere that the G5 macs in late 2005, and mine is included in that category since its a Quad G5, have a much significantly improved coolant system. As I said, I plan to use the machine then in a month trade it up for the mac pro.

Thomas,

Can you do me a favor. Can you look at your G5 Quads cooling system and tell me if its a panasonic one or delphi one? According to everymac.com, the G5 Quads have the improved and better liquid cooling system, where as the earlier models of the G5 PCI-X models did not.

Thanks.
Nadav

Hi, I don't mean to interrupt, but according to everymac.com, the G5 Quads use a more significant better LCS which is not present on the dual 2.7 PCI-X model and the other liquid cooling G5 2.5 Dual PCI-X model.

It seems that the panasonic one is in place on the late 2005 G5s. I might be wrong though.

I don't think you have delphi.. According to everymac.com, the G5 Quads use a much better LCS. The problems of leakage were on the dual 2.7 PCI-X model, and the dual 2.5 PCI-X model which is the earlier 2005.

The Quad core G5s used a much better system. Again, I might be wrong. I am not sure.

Hi, How did you power the pump when testing?

Hi Macdaddi,

Sorry for the delay in replying - been away for a bit. I tested the pump/cooling system using an old PC with a spare molex connection off it's PSU. This worked fine, and the coolant was circulating ok through the Mac's radiator & CPU blocks. In order to get the pump working in the PowerMac itself I was going to remove the molex & replace it with the connector from the original Mac pump. However this is the point where I found that the Mac's PSU wasn't working.

All in all a bit disappointing. I don't have any more time to work on this, so have simply broken the Mac for spares.

Cheers,
Andy

Maybe there are still people having doubts concerning the connectors of both Laing and Swiftech pumps?
I just got a personal mail from Mr. Laing.
The pins of the 4 wire pump are connected as follows:
1. +12V (V control)
2. Tach output
4. V mot (variable)
6. ground
That are exactly the pins of the Apple connector.
I just changed the Delphi/Laing Pump for a swiftech MCP350 (which is produced by Laing and so is identical). The swiftech pump originally comes with 3 wires, black (ground), yellow (+12V) and blue (tach output). When you open the motor housing you'll find a wire bridge between two pins, Take it away and connect the wire from pin 1 instead. Looking on the motor PCB the pins are 6-4-2-1 reading from left to right. Take in mind, that you have to connect both pins 4 and 1 to 12V when testing with an external power supply (or when filling the system).
Not garanteed 100%, my G5 is not tested yet 😉

Paco, any update on your rig? Keep up the great documentation of your workflow. I'm sure fixing this problem is very important to a lot of us G5 users who don't want to spend the money on getting a whole new computer.
As the years add on, It's seems more likely that you will have to burn down your house to show apple that you had a coolant leak before they will replace it.

I worked out some time ago that the pump on my G5 had failed, but I couldn't find a replacement. Fortunately I stumbled across this thread, bought a new pump, some bright pink liquid, tubing and some thermal grease, and a couple of hours work later I now have a happy G5! Later today I'll sort out some pictures and give a run-down of the issues I had when repairing it, (like cracking the radiator...).

Thanks to all that have posted before I now have a properly working Mac again.

Nice thread. Sorry to interrupt...
I have a G5 2.5 dual that has CPU A 20C above normal at idle (70C) and gets as hot as 105C when running. Is it reasonable to say this is a good indication of a cooling system problem as opposed to a failing CPU or power supply?

This leads to... I should be taking apart and inspecting the cooling system. Is there anything else simple to test and rule out before going there?

Thanks for all the info here.

Message was edited by: Jim Newhouser1

Jim
You've described exactly what I was seeing on my dual 2.5. Another problem I had was that the G5 wouldn't boot unless I removed the plastic air-guide. It turned out that the G5 was detecting that the pump was not turning, and so wouldn't boot to prevent damage.

One way for you to tell what's going on is to open it all up, remove the 'G5' cover and feel the various pipes in the cooler unit. They should all be pretty much the same temperature, if not then you've got a pump problem, low coolant through a leak, or a blockage.

Hi Kallisti,

Sorry for the late reply to this thread. For everyone having problems here, this has been a fruitful number to know, Apple Customer Relations at 1-800-767-2775. Explain your problems to them in a nice and respectful way, be persistent, and Apple may come through for you.

Also, while there is no repair extension on the cooling system, there is one for certain Power Supplies.
http://www.apple.com/support/powermac/powersupply/repairextension/

My thought is that if one has a Power Supply within the numbers listed and brought their Mac in to have it replaced, that the Apple Techs wouldn't let it leave with the other problems in place. Of course they'd probably alert you to the other problems and want a lot of cash to fix it, but that's where the number above comes in.

Regardless, that number is the key... Apple is aware of the problems with the G5s on a range of issues, but they are not going to open a Pandoras Box. They will however, if you're fortunate, deal with people and their problems on an individual basis.

I just moved to a Mac Pro recently but prior to that my Quad was the best Mac I ever had (still have). I wish you guys the best of luck.

I have just tried to test my pump from a non-booting late 2004 2.5Ghz G5, it is of the Delphi type. On connecting to a 12v supply as advised here, there is no movement in the pump motor. So can I take it that my pump has packed up? There is just a small spark on connection.

I am in the process of replacing the o rings behind the processor heat transfer plates and on reading this thread decided to change the coolant to non-conductive coolant as well. My plan was to work on the cooling system from the non-booting machine, and to fit it into my 2.7Ghz machine when it is done, but now it would appear that I need a new pump and that maybe it was the failed pump that is stopping the 2.5Ghz G5 from booting.

Has anyone any ideas or advice they can give please? I do not want to remove any parts from my working G5 until I have the replacement system ready to swap over.

One other thing, I was shocked to see the amount of crud etc. that came out of the system when emptied, I suspect that my working G5 also has a crud problem as it will wind up the fans rapidly and quite noisily as soon as the processors start to do a little work, so I have set the processors on reduced in system settings. As I bought the G5 second hand I do not know how quiet or noisy they are normally, and this is the reason for overhauling the cooling system, and of course the fear that a leakage may occur and destroy the whole thing.

If anyone has any info they think may help I would be very grateful.

Thanks Jo.