Powermac G5 cooling block refilling

[pentium]

I got two liquid cooling blocks from two Powermac G5's both suffered the same fate where the O-rings in the waterblock failed. Luckily however I was able to salvage and still have at least one working pair of 2.5ghz processors.
Anyways, the fix for the leak normally is to drain the unit, unscrew and remove the top of the waterblock, replace the O-ring with a newer and slightly bigger one, flush the system and then reassemble and refill it.
I got all those steps done except the last one. Apple welded (it looks threaded but don't try to twist it off as it snaps clean off the radiator and you need a TIG welder to reattach it) some sort of spring loaded valve/connector thing to it. The unit is also under a small amount of pressure at all times. Does anyone have any idea what kind of special connector is needed? I know how to refill it and repressuirze it but no way to actually get the coolant into the thing.

[kc8adu]

Re: Powermac G5 cooling block refilling

looks like a r-134 service valve.

[Wizard]

Re: Powermac G5 cooling block refilling

Pentium, there is so many versions of G5 towers over the years, which one you are working on? 1.5GHz? 1.6Ghz, 1.8? or 2.0?

[pentium]

Re: Powermac G5 cooling block refilling

Dual 2.5 Powermac G5.

Also, would the coupling on this work?

[Wizard]

Re: Powermac G5 cooling block refilling

This?

http://mac.sillydog.org/archives/000245.php

http://www.overclockers.com.au/article.php?id=307166

That fixture that was ripped off is fill/pressurization port. How did you know this is under pressure? You can use antifreeze/distrilled water mix (around 50/50 mix) to refill and no pressure, leave a bit of air bubble for headspace/expansion if this one DOES not have a expansion diaphgram. Which Apple didn't considered including that CRT projector makers are using to prevent coolant from leaking out as coolant expands with rise of heat.

See if you can find a specialized shop that does small welding job with gas shielding welder for aluminum.

Cheers, Wizard

[pentium]

Re: Powermac G5 cooling block refilling

Yep. that's the block alright.
I'm saying it was pressurized because I had the thing sitting on the kitchen table and I thought "Gee, I wonder what would happen if I pressed the valve open?"
I did so and was promptly greeted with a geyser in the face of coolant which got all over the ceiling, walls and the table.

Also, I need to mess with the water/coolant mix a bit. When I opened the blocks it was N A S T Y.

[kc8adu]

Re: Powermac G5 cooling block refilling

looks like they used dexcool (deathcool) in that thing!

[golemmaster]

Re: Powermac G5 cooling block refilling

....
Also, I need to mess with the water/coolant mix a bit. When I opened the blocks it was N A S T Y.

OMG! Ick!

[KeriJane]

Re: Powermac G5 cooling block refilling

Eww.

I like Apple a bunch and wouldn't go near something like that. That's probably not one of their best ideas.

Liquid-cooled electronics worked in the space program and major installations but have no place in consumer electronics. The liquid is going to get out at some point. The cooing systems have to be monitored and maintained. Average customers cannot be depended upon to do this.

It's a wonder the G5 Power Macs worked as well as they did. That must be a very good design to have lasted this long.

My advice is to put that G5 on top of a large cookie sheet, the kind with a raised edge. Big enough to hold all of the coolant.
Keep it there whether it's being used or not especially if the floor is anything other than concrete and most especially if there's a ceiling underneath the floor supporting the G5.


So THAT"S why empty G5 cases are so plentiful!

Glad I waited for the Mac Pro,
Keri

PS. So far as a fill procedure, I'll bet it involves using a vacuum fill device of some kind. that is, something sucks all the air out and then a valve is opened and the coolant is sucked into the unit.

[pentium]

Re: Powermac G5 cooling block refilling

The only reason why this G5 still works is because the absorbent pad below the block caught all the coolant. Any excess then fell into a plastic tray (again, this was installed by apple) which directed it out the back of the case.
I'm pretty sure this is a later revision of the dual 2.5, otherwise I'm sure the latter pad and tray might not even exist.
As I already said, the fix is to replace the O-rings with ones which are slightly larger. I'm sure I can just leave a hose disconnected and bleed the system while I refill it with coolant.

[starky52jmas1125]

Re: Powermac G5 cooling block refilling

If you use a wrench to hold what looks like a hex nut steady and a pliers or vise grip on the farthest out end the valve will screw out. by the way, do you have an extra water block laying around? I was being too effecient and ended up breaking one of the hose connections.

[starky52jmas1125]

Re: Powermac G5 cooling block refilling

use a wrench to hold the hex nut steady and a pliers or vise grip to screw theouter most part out.by the way, do you have an extra water block? I was trying to be thurough and ended up breaking a hose connection off.

[ratdude747]

Re: Powermac G5 cooling block refilling

i think he had fixed as this was from almost a year ago and he has been having psu issues with it.

do not revive old threads unless you are op and have a good reason. if you have a new question, start a new thread (not to be harsh, just saying)

[stj]

Re: Powermac G5 cooling block refilling

the coolant used in those is super-toxic, apple has no end of warnings about them.
i read that if they start to leak, apple would rather replace them for free than have you touch the stuff incase you sue them from your deathbed!!!

[pfrcom]

Re: Powermac G5 cooling block refilling

If you use a wrench to hold what looks like a hex nut steady and a pliers or vise grip on the farthest out end the valve will screw out. by the way, do you have an extra water block laying around? I was being too effecient and ended up breaking one of the hose connections.

i think he had fixed as this was from almost a year ago and he has been having psu issues with it.

do not revive old threads unless you are op and have a good reason. if you have a new question, start a new thread (not to be harsh, just saying)

WHY NOT revive an old thread ?

starky52jmas1125's posting is on-topic, relevant, and could be of interest to someone searching for help

Reviving old threads is not prohibited by Forum Posting rules in FAQs - but what is in rules is point 1) saying use Search feature

[shovenose]

Re: Powermac G5 cooling block refilling

There are two reasons this leaking happens:
1. Its a mac. Nuff said.
2. Water and computers doesnt mix. Watercooling is stupid