Seeking Advice: Refilling G5 LCS.

[ctmpkmlec4]

Yes, I know there are a few write-ups regarding the complete overhaul of the G5 liquid cooling system. However, the ones I have seen are for the DP 2.5 GHz Delphi system, or for the G5 Quads. My DP 2.5 GHz G5 has the Panasonic cooling system, and I assume it has never had any maintenance done.

I notice that my G5 has CPU temps averaging in the 50-60°C range, and to me those temps seem a bit high, especially for normal usage (i.e - not under a heavy load). Did Apple specify maintenance intervals for the LCS?

Here is my main question: Does anyone know how to flush and refill the Panasonic cooling systems?

 

[Surrat]

I know eventually I'm going to have to rebuild the LCS in my quad, and I dread doing it.. I hope your rebuild turns out well.

 

[ctmpkmlec4]

I don't think this system needs a complete overhaul, rather just a flush and refill with new coolant. There are no leaks.

 

[Altemose]

Gavin Stubbs may have some information on this.

 

[128keaton]

Gavin Stubbs may have some information on this.

Gavin is the LCS guy. He wrestled that POS system.

 

[ctmpkmlec4]

I don't think the Panasonic system was the POS. Maybe you're thinking of the Delphi? All I want to do is flush and refill the system, and do so in a manner that is efficient and effective. This thread has 250+ views; no one has any advice regarding coolant type, tools needed, process??

 

[MagicBoy]

I'm no expert, but I'd look at replacing the thermal compound between the LCS and the G5 first, before ripping the LCS apart.

I've seen a couple of guides out there for the Delphi, but not the Panasonic.

 

[MatthewLTL]

Just a thought (as a PC tech not a Mac tech) but perhaps you can get rid of the LCS all together and retrofit G5 heatsinks and the Air cooling? I have heard nothing but horror stories about LC systems on both PCs and G5s. MAYBE you can jerry-rig the 2006 MacPro's cooling system in? Hell, If they can air cool a Xenon processor with HS/Fan systems why not the G5? Can't tell me a G5 runs hotter than an Intel.... exactly why I am a AMD person, AMD Runs cooler and is much cheaper.

Again just a suggestion/question/input... I am not a Mac expert.

 

[ctmpkmlec4]

I'm no expert, but I'd look at replacing the thermal compound between the LCS and the G5 first, before ripping the LCS apart.

I've seen a couple of guides out there for the Delphi, but not the Panasonic.

I think that's a good idea. I had thought about doing this before, but I wasn't sure if it would make a big difference. Worth a shot, though.

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Just a thought (as a PC tech not a Mac tech) but perhaps you can get rid of the LCS all together and retrofit G5 heatsinks and the Air cooling? I have heard nothing but horror stories about LC systems on both PCs and G5s. MAYBE you can jerry-rig the 2006 MacPro's cooling system in? Hell, If they can air cool a Xenon processor with HS/Fan systems why not the G5? Can't tell me a G5 runs hotter than an Intel.... exactly why I am a AMD person, AMD Runs cooler and is much cheaper.

Again just a suggestion/question/input... I am not a Mac expert.

I'm not an expert either, but I am inclined to think there is a good reason why Apple used liquid instead of air to cool these CPUs. I would consider this option if the LCS assembly was leaking. I think there are members of this forum who have had good luck with this conversion. I'm not convinced it's good for longevity.

 

[desantii]

If air cooled can be effectively done would be temped to do a Quad 2.0 or Quad 2.3 just to lower the temperatures a bit...

 

[jbarley]

If air cooled can be effectively done would be temped to do a Quad 2.0 or Quad 2.3 just to lower the temperatures a bit...

I've never heard of a Quad 2.0 or 2.3 until just now.

 

[ctmpkmlec4]

If air cooled can be effectively done would be temped to do a Quad 2.0 or Quad 2.3 just to lower the temperatures a bit...

I don't think it is possible for air cooling alone to be more effective in lowering temps. Water alone is a much better thermal conductor than air. And for this reason, I refuse to do away with the LCS unless it begins to fail/leak. Again, since my G5 has the Panasonic cooling system, leaks are the worst of my worries.

 

[MatthewLTL]

I don't think it is possible for air cooling alone to be more effective in lowering temps. Water alone is a much better thermal conductor than air. And for this reason, I refuse to do away with the LCS unless it begins to fail/leak. Again, since my G5 has the Panasonic cooling system, leaks are the worst of my worries.

Applying the logics in vehicles here; There really is no need to flush or change the cooling unless it is leaking. For example in my car, which is a 2001, NEVER had any coolant flushed or added until the thermostat blew on it. And it was still good after 13 years

 

[bunnspecial]

I've never heard of a Quad 2.0 or 2.3 until just now.

The last generation 2.0 and 2.3 used one dual core 970FX processor, and has a huge heatsink along with 4 fans to keep it cool. I use a 2.0 dual core every day.

The Quad used two dual core 970FX processors. I'd tend to think that if Apple could have gotten away with air cooling, they would have.

 

[ctmpkmlec4]

Applying the logics in vehicles here; There really is no need to flush or change the cooling unless it is leaking. For example in my car, which is a 2001, NEVER had any coolant flushed or added until the thermostat blew on it. And it was still good after 13 years

That actually isn't 100% true. Over time, impurities find their way into the coolant. This can be dirt, or rust from the coolant passages of an engine. The dirt/mineral build up can lead to partially or totally blocked passages and reduced cooling efficiency. Automotive cooling systems are generally sealed, but opening the overflow reservoir to add coolant introduces impurities into the system.
BUT... I totally get what you're saying: The LCS is sealed, so the coolant hasn't been diluted with impurities. And since it doesn't leak, why should the coolant need to be replaced?

 

[jbarley]

The last generation 2.0 and 2.3 used one dual core 970FX processor, and has a huge heatsink along with 4 fans to keep it cool.

The Quad used two dual core 970FX processors. I'd tend to think that if Apple could have gotten away with air cooling, they would have.

I knew that

 

[bunnspecial]

I knew that

Sorry-I wasn't aiming that response at you-I probably shouldn't have quoted you in my response.

 

[MatthewLTL]

That actually isn't 100% true. Over time, impurities find their way into the coolant. This can be dirt, or rust from the coolant passages of an engine. The dirt/mineral build up can lead to partially or totally blocked passages and reduced cooling efficiency. Automotive cooling systems are generally sealed, but opening the overflow reservoir to add coolant introduces impurities into the system.
BUT... I totally get what you're saying: The LCS is sealed, so the coolant hasn't been diluted with impurities. And since it doesn't leak, why should the coolant need to be replaced?

i should of rephrased that... My coolant back in 2013 was good enough (coolant tester) to still be considered within acceptable range. (Still good up to -25F IIRC)... than the Thermostat blew.

 

[desantii]

The last generation 2.0 and 2.3 used one dual core 970FX processor, and has a huge heatsink along with 4 fans to keep it cool. I use a 2.0 dual core every day.

The Quad used two dual core 970FX processors. I'd tend to think that if Apple could have gotten away with air cooling, they would have.

Yes, so if I could do a quad core 2.0 air cooled would choose that and not have to worry about LCS. I have a quad to rebuild and tempted to go the air cooled route for a 2.0 or 2.3. Just use two 2.0 dual cores...

 

[Surrat]

Just want to point out that the single core dual cpu 2.5, and 2.7 G5's CAN be converted to air cooling.

I did it with my dual 2.7 and have had no problems at all. I used the heatsinks from a G5 dual 2.0 on it. So, if your plan to reload the LCS fails, you can always fall back on converting it to air cooling.

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Yes, so if I could do a quad core 2.0 air cooled would choose that and not have to worry about LCS. I have a quad to rebuild and tempted to go the air cooled route for a 2.0 or 2.3. Just use two 2.0 dual cores...

The air cooling heatsink on the dual core 2.0 and 2.3 will not work on 2 cpu's. Its an extra wide heatsink, taking up about 1.5cpu's of width. If it was that simple i would have converted my G5 quad to air cooling. There is no room to mount 2 of the dual core air cooling heatsink units in the G5. To create a quad 2.0 like your thinking, you would have to use the original quad LCS, since nothing else will fit. We need a bored engineer with CNC system to create heatsinks for the quad.

 

[desantii]

How about using heat sinks from a dual 2.0 to build a quad 2.0?

 

[Surrat]

How about using heat sinks from a dual 2.0 to build a quad 2.0?

You cant, the heatsinks for the single core G5's dont fit on the dual core G5's. The dual cores use 2 heat pipes for the cpu vrm cooling unit, single core ones use 1 heat pipe. If you were able to recut some custom aluminum mounts and trim down the original dual core heatsinks, it might be possible.

 

[Lammer]

I could use some help too

Hi All
I'm a Noob here so sorry to jump in rather than starting a new thread.
I recently aquired a G5 quad 2.5ghz off ebay (non working no chime cyclonic fans and so on ) no HDD
Turned out to be a memory issue.
However when I started the machine there was a fan like noise that comes from the bottom pump. Dual delphi pump system grey cover with cooligy or something like that (sounds like pump may be running dry)
I have removed the entire assembly and stripped the processors no visible leaks.
The cooling blocks are solid copper design and don't have O rings as other LCS do. All the pipes are epoxyed on and clamped From what I can find this is the belt and braces Mk2 LCS? I'm assuming either a faulty pump or no fluid although with no evidence of a leak seems unlikely either way a strip down/rebuild is inevitable.
Has any body delt with this system as my question is how to remove the pipework without damaging the fittings and how to bleed the system once rebuilt and refilled I also asume the pump is the ddc1 type should I need to find a replacement? I was also thinking of modding the pipework by adding "T" pieces and bleed valves so future work would be easier?
The other question is if I re- engineered the system retaining the cpu heat blocks but fitting a different pump rad will it work or is the pump configuration intergrated in such a way that would cause problems if it were removed?
Thanks in Advance

 

[Surrat]

Well, my G5 dual 2.7 runs fine with the water pump unplugged since its now air cooled. However, if I try to run Apple Service Disk to calibrate it, it fails saying a fan is not working, even though they are. I think its failing because the pump isnt there, since if I connect the pump, and just leave the LCS next to it to run, the error stops. It still fails later, since one of my 2.7 cpu's has a bad temp diod.

As long as your cpu's are good, and you leave the main fans connected, you can unplug the water pump I'm sure and use a PC cooling setup if you can make it fit.

About yours, if its two pumps, its the less reliable type for the Quad. Consensus seems to be the single pump version is best of all for G5 Quad.

 

[Lammer]

Well, my G5 dual 2.7 runs fine with the water pump unplugged since its now air cooled. However, if I try to run Apple Service Disk to calibrate it, it fails saying a fan is not working, even though they are. I think its failing because the pump isnt there, since if I connect the pump, and just leave the LCS next to it to run, the error stops. It still fails later, since one of my 2.7 cpu's has a bad temp diod.

As long as your cpu's are good, and you leave the main fans connected, you can unplug the water pump I'm sure and use a PC cooling setup if you can make it fit.

About yours, if its two pumps, its the less reliable type for the Quad. Consensus seems to be the single pump version is best of all for G5 Quad.

I think the 2 pump on my quad is the later model no o rings on the blocks so it can't leak only from the joints and they are sealed with epoxy
The system hasn't leaked looks like the delphi pump has failed?
I think they did a 2 pump for the duals and thats the one that is not very good? I've only seen my set up in 1 thread and the chap hadn't started on it at that point
An update I spent a while looking at it today it is possible to remove the epoxy from metal parts i.e the rad and the metal pipes going down to the cpu blocks. I decided to experiment on the blocked off outlet on the rad this looks like the pipe is just squashed up then a rubber boot epoxyed over it.
I may cut the pipe back to reopen it and fit a hose there with a valve on the end for servicing in future . I think the way forward may be to cut the pipes between the pump and rad clean epoxy off metal parts fit new pump and hoses and flush out and refill if the epoxy comes off the removed pump ok II'll do the other side the same as I will have a spare pump top if I break the other one taking it apart. I know you should do both sides but if its not broke and there is a good chace of breaking it in the process then best left alone?
As you say could cobble a frankinstien PC setup in there using the mac rad and cpu blocks and a larger pump and modified plumbing.
Can someone confirm is the rad 2x rads in one as it has 6 in/outs if you count the 2 that are sealed off?