Brake Master Install

Steve,

Welcome to the bulletin board !!

I am just up the 99 from you in NW Fresno.

Swapping MC's should be plug and play, but...

Another local P-car owner made a swap and had lousy braking afterwards. Bled again, no change. I finally started quizing him on the swap. He had retained the original pushrod as it had a threaded adjustment feature and he thought that was good thing to retain. But when we pulled it and compared it to the rod included with the new MC, the length difference was very notable.

So, talk to us about the pushrod and if you perhaps did something similar?

Also, would you please drop me an email off-list so we can obtain contact info.

fresnofinches at aol.com

Larry

Thanks for the reply.. I used the plunger that came with the unit from PI. I do not think it is to long because there does not seem to be a pre load on the master when it is bolted up. I am thinking it is too short and making an adjustment on the rod end inside the car might make a difference. i did re bleed the brake with extra care on taping the bleeders to prevent air and as I mentioned the pedal is solid whith no bleed down when there is no vacume on the booster. I will send me email shortley.

I just swapped out my master and had the same problem. Did you bench bleed the MC prior to installation. I got lazy and skipped that step. After getting the soft pedal like yours, I bench bled it and it solved my problem. I don't know why the symptom doesn't show without the motor running. In any case, this is what solved my problem.

Thanks for the idea, but I had bled the cyl on the bench, before the install, ( like you learned my lesson ), after removing the cyl I found the plunger supplied by the vendor too short for my application and after experimenting with shome shiming to different lenghts I was able to correct the problem. Thanks for the input.

quote:

Originally posted by 4NFORD:
I just swapped out my master and had the same problem. Did you bench bleed the MC prior to installation. I got lazy and skipped that step. After getting the soft pedal like yours, I bench bled it and it solved my problem. I don't know why the symptom doesn't show without the motor running. In any case, this is what solved my problem.

Once I tried pressurizind a master Cyl fo bleeding purposes. (I was experimentng). Problem was I emptied the MC too quickly and voided it of fluid. At this point the best thing to do would be to re-bench bleed it. Instead, I hooked up a very large syrenge (horse syrenge) filled it with about 80% fluid, drew some from the caliper holding it up so no airbubles would be re-introduced then fed the fluid back through the line. This bled the MC just fine.

Also, with general bleeding, I use a tank and a vacume pump. It makes self bleeding a little easier:



I should update the photo though. I have the vacume tied to the other end of the tank.

HF has a cheap vacume pump. I wonder how well it would work.

Gary