PM G5 2.5ghz Quad LCS removal

Discussion in 'PowerPC Macs' started by Amigaz, Feb 20, 2011.

  1. Amigaz macrumors newbie

    Amigaz

    Joined:
    Sep 28, 2009
    Location:
    Stockholm, Sweden
    #1
    I'm in the process of removing my LCS unit from my Power Mac G5 Quad to inspect and rebuild it but am not 100% sure how to remove it because I haven't found any good guide on the net that matches my cooling system.
    For example the cooling system in this guide doesn't match mine:
    http://www.xlr8yourmac.com/systems/G5_CoolantLeak_Repair/G5_CoolantLeak_Repair_p1.html

    Some of my screws seem to be hidden that you have to loosen to remove the LCS untit for the chassi.

    Here's my LCS unit:

    [​IMG]

    Any help and tips on how I should proceed would be highly appreciated
     
  2. skinniezinho macrumors 6502a

    Joined:
    Jan 1, 2009
    Location:
    Portugal
  3. photonorm macrumors member

    Joined:
    Mar 2, 2011
    Location:
    Memphis, TN
    #3
    O-ring size

    I am currently repairing my LCS for a PowerMac G5 dual 2.5. The reference guide at the xcelr8 site is a great resource to help, however, you should measure the O-rings needed for your machine to make sure you order the correct size. I didn't and ordered what they recommended, which was for a dual 2.7 and they were too big.
    You might want to check out this site http://home.earthlink.net/~strahm_s/manuals.html and see if you can find the manual for your machine.

    I had to really search to find the coolant. I had to do a search for the product number to find a site that had it. The name of the company is Performance-PCS out of Florida. http://www.performance-pcs.com

    Oh ya, when you get to the part when you are going to remove a tube to let out the coolant, it might be under pressure so have goggles on and protective clothing so you don't get covered.

    Good Luck!

    Norm
     
  4. Amigaz thread starter macrumors newbie

    Amigaz

    Joined:
    Sep 28, 2009
    Location:
    Stockholm, Sweden
    #4
    Thanks for all the tips/help so far, guys

    Still waiting for my 3 and 4mm hex screwdrivers to arrive

    I'm still unsure on how to fill the system with coolant when I've rebuilt it...it's not built up like a PC LCS exactly
     
  5. photonorm macrumors member

    Joined:
    Mar 2, 2011
    Location:
    Memphis, TN
    #5
    LCS refill

    Morning,
    I found this site last night that might help you out regarding refilling the LCS.
    http://kitspy.com/2009/10/leaky-powermac-g5/

    I have found a couple of other posts elsewhere that also ran the pump or used a different method of running the coolant into and through the radiator to get out all the air or as much as possible.

    I also read on a post that the LCS pump was making some noise after refilling. He said that it could have been from some air in the system or perhaps some 'crud' that attached to the impeller inside the pump.

    I am going to see if I can open up my pump and see if there is any 'crud' in there and clean it out since I have the machine and LCS already in pieces.

    Finally, I noticed in the link I listed in this site that the author was able to find the o-rings at a local, non-big box, hardware store. I am going to try my luck and do the same. I will keep you posted.

    Norm
     
  6. Amigaz thread starter macrumors newbie

    Amigaz

    Joined:
    Sep 28, 2009
    Location:
    Stockholm, Sweden
    #6
    Mornin'? it's 16:39 here (4:39PM) lolol :D

    Gotta stock up on those o-rings...have a dealer here who I think has them in stock in the viton material
     
  7. photonorm macrumors member

    Joined:
    Mar 2, 2011
    Location:
    Memphis, TN
    #7
    Extra O-rings!?!

    If you happen to find some and they fit let me know where. I am now thinking that if my fix works I can rebuild some used machines :)

    I am going on an expedition to find some locally. Let the hunt begin!
     
  8. 666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #8
    Guys, contact OrangeSVTguy. He's done LCS rebuild in his Quad and may have some info about parts suppliers.
     
  9. Tailpike1153 macrumors 6502a

    Tailpike1153

    Joined:
    Aug 31, 2004
    Location:
    Bellevue, WA
    #9
    Thanks for the tip.
     
  10. OrangeSVTguy macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #10
    Thanks

    Here and subscribed lol.

    I replaced the stock tubing in mine with Tygon tubing and I reused the old clamps. I used Feser One fluid as that seemed to be the best solution since it is stated to be non-corrosive and non-conductive of electricity so if it were to ever leak it won't self-destruct the entire G5. I don't have a guide anywhere but I did have a thread somewhere with pictures. I only had the single pump version as I guess the dual pump was an updated version.
     
  11. photonorm macrumors member

    Joined:
    Mar 2, 2011
    Location:
    Memphis, TN
    #11
    New O-rings on order

    I have new o-rings on order and will arrive on Monday. They are one step smaller than the ones mentioned in the fix for the dual 2.7 at http://www.xlr8yourmac.com/systems/G5_coolant_leaks.html.

    I spoke with a tech person at MCS Industrial Supply about the best o-ring for this application and he recommended the Viton, which is the same compound for the o-ring in the xlr8yourmac.com site.

    I am going to start a new thread with a more detailed explanation of the steps in the repair on my machine.

    I will update here as to the result of the new o-ring.

    Norm
     
  12. Amigaz thread starter macrumors newbie

    Amigaz

    Joined:
    Sep 28, 2009
    Location:
    Stockholm, Sweden
    #12
    The hex tools has arrived so I started loosening the LCS unit step by step using the service manual from Apple.

    Evening though I followed the manual and I'm no newbie when it comes to loosening screws, following service manual (use to work as an outboard engine mechanic) I can't remove the LCS unit..it's stuck! it feels like I'll break something if I use more force

    According to the manual it's a matter of lifting the LCS unit straight up out of the case:

    [​IMG]

    Anyone got any idea's? :confused:
     
  13. OrangeSVTguy, Mar 13, 2011
    Last edited: Mar 13, 2011

    OrangeSVTguy macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #13
    Sounds like you missed some of the screws. I don't know specific how many screws hold down the dual-pump assembly but I do know that there were 4 hex screws in the back(far right if looking at it from the side) that supplies the power to the CPUs, these attached to the visible part of the CPUs PCB board.

    Then there were 4 more hex screws on holding the assembly down near the CPU power screws. 4 more in after the radiator, these don't come out, they "float" in the assembly and these are what keeps pressure from the CPUs to the logic board. 2 in front of the radiator.

    I can't be certain as the dual-pump has more obstructions so be sure to look all around for the screws.
     

    Attached Files:

  14. Amigaz thread starter macrumors newbie

    Amigaz

    Joined:
    Sep 28, 2009
    Location:
    Stockholm, Sweden
    #14
    Have loosened all those screws you mention and according to the service manual, I've fololwed it to 110%
    Can it be the expander "pins" that the bolts go into that are still holding the LCs unit somehow?
     
  15. Amigaz thread starter macrumors newbie

    Amigaz

    Joined:
    Sep 28, 2009
    Location:
    Stockholm, Sweden
    #15
    Ok, some progress here....managed to loosen the LCS beast...the blue, rubber thingie on the pic below was the thing that was still keeping it from coming loose...like trying to remove a cylinder head on an engine when the gasket sealing compound on the head gasket is keeping the head from coming loose

    [​IMG]

    Next question is...what is the best way to proceed now to remove the cpu's?
     
  16. OrangeSVTguy macrumors 601

    OrangeSVTguy

    Joined:
    Sep 16, 2007
    Location:
    Northeastern Ohio
    #16
    Congrats on the completion of the easiest step :p lol

    Just take out all the black hex screws. All the screws goes through the PCB into the bottom of the assembly bracket except for the one in the middle of the copper heatsink, that hold the heatsink to the CPU board. Once all the black hex screws are removed, slowly loosen the 4 screws holding the CPU to the waterblock in a clock-like fashion. Then lift off the CPU board from the LCS assembly. You have to swing it back as the heatsink on the back attaches to the top of the LCS.
     

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