NigeW

Q: Power Mac G5 Quad LCS Repair

Hi again. Whilst servicing my LCS I had the misfortune to break the outlet pipe fom processor A's heat transfer block. (For anyone attempting to remove the factory fit tubes DO NOT try pulling them off-cut them above the barbed pipe with snips and then carefully cut them lengthwise with a craft knife and peel them back). I first tried repairing it with super glue  to no avail and then tried araldite rapid which formed a strong bond. I was concerned that any bending moment would break the join so to minimise this I cut a 3mm length of the new clear PVC tube, slid it down to the base of the pipe and liberally coated in more araldite. To further reduce bending I moved it to processor B's slot as the pipe for that is more upright. I filled the system with a 50/50 mix of antifreeze and distilled water. I then spent hours bleeding the system without much success. I was reappraising my approach to this when I noticed that coolant was leeching out from under the araldite. If anyone has been in this predicament themselves, I would appreciate any advice on the best adhesive to use that hagood strength and sealing capabilities. Thank you in advance. Nigel29012012284.jpg

PowerMac, Mac OS X (10.4.11), G5 Quad

Posted on Feb 2, 2012 7:30 AM

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Q: Power Mac G5 Quad LCS Repair

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  • by BDAqua,

    BDAqua BDAqua Feb 2, 2012 12:17 PM in response to NigeW
    Level 10 (123,633 points)
    Feb 2, 2012 12:17 PM in response to NigeW

    I first tried repairing it with super glue

    Super glue is water soluble. They even use it for Brain Surgery because it dissolves after time.

     

    Hopefully you get more replies here.

  • by NigeW,

    NigeW NigeW Feb 2, 2012 1:19 PM in response to BDAqua
    Level 1 (0 points)
    Feb 2, 2012 1:19 PM in response to BDAqua

    Thanks for that but as I said super glue didn't work at all, which going  by what you said about it's solubility in water is a good thing! The port is made from a very strange plastic. When you drop it onto a solid surface it rings like metal. It reminds me of the old bakolite/paxolin used in vintage electronics. I'm presently Googling/contacting glue manufacturers so I'll see where that takes me. After recently installing a new logic board I'm hanged if I'm going to let this little problem force me to disassemble the quad and sell it for spares!

  • by Heikki Lindholm,

    Heikki Lindholm Heikki Lindholm Feb 2, 2012 11:34 PM in response to NigeW
    Level 1 (135 points)
    Feb 2, 2012 11:34 PM in response to NigeW

    Maybe a strategy similar to the following would help:

     

    http://skinneelabs.com/ddc-vaporti/

     

    http://www.xtremesystems.org/forums/showthread.php?140851-my-Laing-ddc2-pump-top -mod-%2856k-warning%29&s=170195a9e755fd24747defb00e12396b

     

    The main problem being, of course, the very little extra clearance for anything on top/sides of the CPU block cover. You could also try to create extra sealing inside the broken outlet. Sanding the plastic a bit might help the glue to bond better.

     

    And you can always run the Quad as a Dual with a single CPU card. Just route the LCS hosing through one CPU block only and cap the other outlet from the rad.

  • by NigeW,

    NigeW NigeW Feb 5, 2012 11:10 AM in response to Heikki Lindholm
    Level 1 (0 points)
    Feb 5, 2012 11:10 AM in response to Heikki Lindholm

    Thanks for that information Heikki. Unfortunately before reading it I'd purchased some Plastic Padding "Super Steel" 2 part epoxy. This stuff is supposed to be capable of repairing central heating radiators and is used in industry for making prototypes. I repaired the port on Friday and to be honest it appeared to do a good job. I have just spent the weekend filling the LCS/bleeding it and running the pump to make sure there were no issues and the bloody thing has broken again. Thank God I hadn't fitted it!!! This repair is costing a fortune in adhesives-surely if we can put a man on the moon we can come up with an adhesive that works on this type of plastic?? And I had gone from a 50:50 water/anti-freeze mix to 80:20  in case the anti-freeze was the culprit. Have you any idea who originally manufactured these covers, as a new one has to be the way to go? Thanks. Nigel

  • by Heikki Lindholm,

    Heikki Lindholm Heikki Lindholm Feb 5, 2012 1:47 PM in response to NigeW
    Level 1 (135 points)
    Feb 5, 2012 1:47 PM in response to NigeW

    The LCS design is by Delphi. I've no idea who made the covers, sorry, but finding new ones...very unlikely. Best bet would be ebay or Apple service centers.

     

    See this:

    http://www.cpchem.com/bl/rytonpps/en-us/Pages/AdhesiveBonding.aspx

     

    I'm not 100% PPS is the material but could well be, the pumps use PPS-GF40.

     

    Also this fairly recent message came to mind:

    http://forums.macrumors.com/showthread.php?t=1229554&page=2

    Maybe the offer still stands.

  • by NigeW,

    NigeW NigeW Feb 7, 2012 12:44 PM in response to Heikki Lindholm
    Level 1 (0 points)
    Feb 7, 2012 12:44 PM in response to Heikki Lindholm

    Thanks for all your input Heikki. I contacted Huntsman who are the manufacturers of Araldite and surprisingly got a very detailed reply from their technical department. To summarise they suspected the failure was due to the epoxy not bonding with the surface due to poor surface preparation, that Araldite is not affected by anti-freeze and that after preparing the piece (i.e. sanding down and cleaning with acetone), I should apply it in layers. I did all the above last night and today refilled the system. It seemed fine so I installed the c.p.u.s, threw it all back together (getting quite profficient at this now!!) and switched on. Idle temps were within 2 degrees of each other at 35. So I went into energy saver, set the processors to max and fired up folding. Temps rose to 50 and were stable and the machine quiet. Rebooted and ran thermal calibration which passed. Started a full diagnostic and had a quick look at the repaired port.****ing thing was hanging off!! Whipped out the mains lead and tilted the case towards me. For once I had luck on my side-there was a large bubble at the port which prevented any fluid coming out. So back to square one. I don't care what Huntsman says-the Araldite had gone from being rock hard to soft and pliable and had absorbed the blue colour from the coolant. I'll contact the guy on macrumors and fingers crossed he's still got it. Failing that I've come up with a new repair strategy-fibre glass. I've used this to patch up holes in a rusty car and it was very effective. I think cutting the matting into fine strips and wrapping them around the base of the pipe might do the trick. I certainly hope so! ( I'm at the stage now where I've threatened the machine that if my next repair doesn't work it's getting Hackintoshed :-) )Nige

  • by Skorpan,

    Skorpan Skorpan Mar 4, 2012 5:37 AM in response to NigeW
    Level 2 (375 points)
    Mar 4, 2012 5:37 AM in response to NigeW

    Hi,

    I have the same problem, I have a dual 2.7 and I also snapped one of the heat tranfer barbs off, here's what I did.

     

    Super glue to hold the barb in place, then 'JB Water Weld', this is a cold weld which sets hard and can be filed after it sets. I have read a couple of mac users have used this to good effect.

    My break was clean and the super glue worked really well, although it seems it's not waterproof, but I am only using it to ensure the JB Water Weld will be in the right place for a tight seal.

     

    I am still on the hunt for a 'new' heat transfer block, and if, by some miracle I find any I will let you know, maybe you can do the same?

     

    Good luck

    Anthony

  • by Pheidius1,

    Pheidius1 Pheidius1 May 3, 2016 3:56 PM in response to NigeW
    Level 1 (15 points)
    Desktops
    May 3, 2016 3:56 PM in response to NigeW

    I have a less dire problem. I can't seem to find a thermal paste that my LCs likes. What do you recommend?