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Quad G5 Liquid Cooling System overhaul help

So, since my Lenovo Core 2 Duo died (worthless computer..), I've been without a laptop. This also means I'm using my Beige G3 for all my internet and computing needs.

I suppose that might be fine if everything out there (the internet included, and perhaps especially) weren't horribly-programmed bloatware.

Anyway, a few months ago I got a Quad G5 off eBay for $150, As-Is. What turned out to be wrong with it is that the LCS needs to be overhauled; unless I run it in "Reduced" mode in Energy Saver, it crashes within ten to fifteen seconds of use at full speed, after hitting over 200F.

Only problem is, I"m not quite sure what tools I need.

It's a Quad G5, with the Delphi LCS block. Can anyone link me to EXACTLY what tools I need to take the thing apart? I know I need some sort of Hex screws and torx screws, but do NOT know what size. I know I need O-Rings, but don't know how to meausre them exactly, so I don't know what size I'd need. I *DO* know what kind of coolant to use... I don't really know what sort of tubing to buy.

Please help? I really like the Quad, it's very fast... and that's at literally 1/2 speed. But I certainly can't justify upgrading it yet without being able to use it at 2.5 GHz instead of 1.25.

Help is much appreciated. Again, what I need is the specs of tools I need, quite preferably links to exactly what I need. I know XLR8YourMac etc. have done a lot of detailed guides on this, but they weren't on Quad G5s, and AFAIK the tools necessary are slightly different for a Quad. Thanks!

PowerMac, Mac OS X (10.5.8), Quad G5, 1.5 GB RAM, 750 GB, 7800GT

Posted on Oct 3, 2011 8:32 AM

50 replies

BDAqua

Level 10

239,225 points

Nov 7, 2011 11:32 AM in response to BMaverick

Thanks for the info! 🙂

Nov 8, 2011 12:23 PM in response to BMaverick

According to the MSDS the Delphi A2 coolant in the OP's Quad is 80% DI water 15% propylene glycol. That doesn't sound very harsh.

Nov 8, 2011 12:34 PM in response to Heikki Lindholm

What's the remaining 5% ? 😮

Nov 9, 2011 5:51 AM in response to Heikki Lindholm

QUOTING: Heikki Lindholm "According to the MSDS the Delphi A2 coolant in the OP's Quad is 80% DI water 15% propylene glycol. That doesn't sound very harsh."

My reference is with the A1 coolant, the first type used. That was the harsh coolant.

QUOTING: Ramón G Castañeda "What's the remaining 5% ?"

The remaining 5% is more proprietary corrosion inhibitors for the A2 coolant. Thus, my remarks to use the Sierra PG at 33% to 66% DI or DW or RO if neither can be had. You have no idea what the other inhibitors actually are nor where to obtain them.

If a rebuilt loop uses 80% DW with 15% PG, they will indeed run into trouble. The second gen-LCS micro-channels will gunk up in time with corrosion. This is the reason when some of the threads here are talking about water-blocks having a higher heat load vs. the other one in the loop. In some cases up to 50%. The Sierra PG coolant had been tested extensively in the G5 LCS development and proven to be a good solution.

Nov 9, 2011 9:50 AM in response to BMaverick

Thanks for the thorough elaboration.

Quad G5 Liquid Cooling System overhaul help