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  1. #1
    Scott Walker for President. SSmike1's Avatar
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    Brake MC VS Clutch MC, WHY?

    OK,
    now that i know the 2004 McLeod Clutch Master Cylinder in my car died,
    the Rubber Puck deteriorated, letting air in.

    WHY? why does this happen?

    i have never had a BRAKE MC go bad,
    nor any STOCK Clutch MC go bad.

    whats up? anybody know why?

    thx
    mike
    2000 SS camaro

  2. #2
    have pot, will stir WickedSix's Avatar
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    dunno about this particular model but i've had two brake mc's and one clutch mc and sc go bad.... usually just excessive seal wear....hasn't happened to me out here but i use to live in the mountains (read as ALOT of hard long braking and tons of gear shifts) contamination and abundant use... how long did it live out of curiousity?
    -Patrick


    I r teh have da kewl now cuz of that ^^^^^^

    "It's not a racecar if it drives to the track and goes home on a flatbed apparently"

  3. #3
    Mike, if you take apart the master, look at the edges of the seal. You will probably notice small tears in the seal caused by an incomplete machining of the cylinder bore.

    Buy the repair kit from McLeod, about $40-50 or so, and before you reassemble it, run a brake-cylinder hone down the bore and smooth it out before you reassemble it.

    I am sure if your piston is rip on the sealing edge, if you talk to the guys at McLeod they will explain the same procedure because they had this issue for a short period of time...

    If you look on LS1Tech you will notice a bunch of threads regarding this.

    I have the same clutch master in my T/A.

  4. #4
    they still have the issue going on dennis. I had a 1st gen mc and now a final version and they still have issues with the boring process so they stopped selling/making them. sucks they arent giving them for free anymore, the last 3 rebuilds I have done this year alone were all free.

  5. #5
    Scott Walker for President. SSmike1's Avatar
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    ok, ill do that, thank you.

    use,
    the car today has 45K original miles, i replaced the Clutch MC in 2004, with a mcleod 139001 MC. it had 15K miles on it at the time, so...
    it has 30K miles on it, most of those miles are on Race Tracks,
    I race the car at MFBA events at Road America,
    and NASA TT, time trial events,
    and MC midwestern council Auto cross events, = lots of shifting.

    all i can say is, this car is awesome,
    i have 30,000 race track miles on this car, and it just keeps on going!
    2000 SS camaro

  6. #6
    Scott Walker for President. SSmike1's Avatar
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    i called and they sent me to a CNC machining company,
    who does their rebuild kits now.
    CNC = 1-619-275-1663 = phone #
    and they wanted $35 for the rebuild kit 910ML
    for the 2004 Era MCLEOD Master Cylinder...

    mcleod does not sell or give them away anymore.
    2000 SS camaro

  7. #7
    Newbie wrencher's Avatar
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    The cylinder is made with parts not really suited for a master cylinder is the primary problem. If you look at the internals for a brake master it has much higher quality seals. The McLeod has one seal & it was taken from a wheel cylinder.

    Then the concentric slave set up needs a lot of pressure potential to move the pressure plate diaphram spring.
    It dont have the mechanical advantage of a clutch fork/slave set up.

    Then the concentric slave design has the tendency to gain heat much easier & rapidly.
    Heat & crappy fluid kills these things.
    Thats why I got into the habit of keeping the pedal depressed to a minimum.

    When I was drag racing the car a lot, used to flush it every trip from the track.
    It would darken the fluid in 1 day with that McLeod lol.
    I was also holding 5-6K @ the line with a 2 step though.

    Got the Tick now it cured all those problem for me.
    I run the master & line from them with a stock style slave.
    That & a coil sprung 3 finger Mcleod pressure plate.

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