Brake Troubleshooting, PMB all around |
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Brake Troubleshooting, PMB all around |
OU8AVW |
Sep 21 2014, 10:03 AM
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#1
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Yacht Rigger Group: Members Posts: 1,803 Joined: 1-October 08 From: Granbury, TX Member No.: 9,601 Region Association: Southwest Region |
So I'm getting to bleeding my brakes. I have replaced every item with parts from PMB. That's all the hard lines, soft lines and all calipers and pads. The installation was pretty easy but I'm not beyond making mistakes. The stuff has been sitting a while, installed with no fluid in the system.
Please note that I've done this on quite a few VWs so bleeding brakes is not foreign to me. I just did this exact process on my '89 Westy with good results. (IMG:style_emoticons/default/sheeplove.gif) I can get a steady stream of fluid through all bleeders both with a vacuum pump and also with pedal action I see no signs of leaks I get no pedal and it seams that the pedal won't actuate any of the calipers (More on this) with normal action. This morning I went though all the calipers and moved a considerable amount of fluid though them by pumping the pedal with similar results until.... I pumped the brakes a bunch and finally got action on the front brakes but then they were stuck. No action on the rears. I did not bench bleed the master. I did crack the hoses on the master until I got fluid from each of them. I have speed bleeders installed, so far I am not a fan. What could I have messed up in the install? Why are these things sticking? Next step? Thanks..... |
earossi |
Sep 21 2014, 06:05 PM
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#2
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Member Group: Members Posts: 210 Joined: 8-December 11 From: Chicago, Il Member No.: 13,878 Region Association: Upper MidWest |
I just went through this on my car. We pushed over two pints of fluid through the system using a pressure bleeder. The MC was bench bled before installation.
In the end, I focused on two areas: the proportioning valve and the master cylinder. Since I had fitted staggered wheels on my car (8 rears and 7 fronts), I was not concerned about locking up the rears, so saw little value in retaining the proportioning valve. I replaced it with a Tee fitting that a number of folks have used for that purpose. That did not fix my issue. I could push on the brake pedal and watch it go to the floor. So, that left only the master. Even though we had bench bled the assembly, I decided to slack off on the outlet line nuts as had been recommended on this sight. I backed both nuts off just enough so that I could see a slow seep of brake fluid at each nut. We left the car to gravity bleed in this fashion for a couple of hours. Once done, we tightened the outlet nuts and topped off the reservoir. We had a hard pedal! Never seen this phenomena before on any of my other cars, but apparently there is an area within the MC configuration where some air can reside despite normal bleeding procedures. So, give it a try. You did mention in your narrative that you had bled the MC at the outlet ports........but, did you allow it to slow bleed for a couple of hours? |
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