Master Cylinder Clunk in Reverse

Discussion in 'The Garage' started by lutter94, Aug 11, 2015.

  1. lutter94

    lutter94 Well-Known Member

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    I swapped to Cobra brakes this spring, and contrary to what I should have done, I did not verify my push rod depth, only assumed it was the same. The brakes have always felt good, maybe a small amount of play, but wasn't bad. Anyways, it seems to almost a clunking noise in reverse when i hit the brakes. Doesn't do it in forward, but thinking its a push rod depth issue.

    Yesterday and today, I've been playing with push rod adjustment (not disconnecting the mc, only pulling it forward). Always made small adjustments, and didn't see a lot of improvement. At one point early, I thought I went to far, and shortened it a couple 1/8th turns. The sound was worse. After doing some small adjustments today, and seeing no changes, I lengthened it 3 1/8th turns, and it seemed the same. Decided to drive to a friends house to have him listen under the hood, at slow reverse speeds, to verify that it is indeed the mc making noise, but he was not there. On the return trip idk what happened, but it was like my brakes were always on, I had a very firm pedal, and decelerated with the clutch in. Pulled into the hospital parking lot (first exit on right), and shortened 2 1/8th turns. Now it seems back to the way it always was. Pedal feel while driving fwd does feel a little better than it had been in past, but doesn't feel like its dragging, and still makes noise in reverse.

    Any thoughts? Comments? Questions?

    Anyone have the instructions a new master cylinder comes with? Can't seem to find anything online, and just sent an email to Maximum Motorsports asking for instructions.

    Thanks!
     
  2. 07GtS197

    07GtS197 Well-Known Member

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    Take the calipers off and check the pads for uneven wear. Otherwise it could be the pushrod but I doubt it.
     
  3. lutter94

    lutter94 Well-Known Member

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    Will do, it just sounds like its coming from in front of the firewall, MC location...
     
  4. 07GtS197

    07GtS197 Well-Known Member

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    I understand but I think its best to take the calipers off and check the calipers and slide pins to rule those out. This is probably a dumb question but did you bleed the master cylinder and break in the brakes?
     
  5. lutter94

    lutter94 Well-Known Member

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    Yea, these are those powerstop ceramics, had the break in procedure i've already done to the fusion. I'll pop em off this wknd, don't have the greatest tools here to do it. When I swapped it all, I put new stainless lines on the front calipers, new master cyl, cobra mc hard lines, and bled the entire system after install. The rears are still soft lines, since I plan to put cobra rears on it, and just ordered the cobra stainless line kit. Rears do not work in the GT orientation.
     
  6. lutter94

    lutter94 Well-Known Member

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    Ok, had someone outside the car for me, it is the calipers making noise. Will inspect tomorrow.
     
  7. 07GtS197

    07GtS197 Well-Known Member

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    I bet the slider pins arent lubed enough. Check your pads to see if theyre worn unevenly now too.
     
  8. lutter94

    lutter94 Well-Known Member

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    Will do, thanks :)
     
  9. 07GtS197

    07GtS197 Well-Known Member

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    No problem man, and if you need more help just post up man