Hi all. I've just completed an overhaul of my Girling / ATE / Bosch ABS brake system to include master cylinder, booster, brake calipers, hoses, hardware, pads and rotors. The entire system was flushed and is immaculately clean and sealed.

My problem is an EXTREMELY sensitive brake pedal. When depressed, it engages excessively hard such as I'm jamming on the brakes. The system seems "over-boosted" and I wonder if I received a defective booster (rebuilt) or there is an adjustment I missed.

I have altered the pushrod adjustment to different settings and while changing the pedal height and engagement, when engaged the system still brakes excessively hard.

Any thoughts or ideas folks? Bad booster? Bad caliper(s)?

Thanks.

John

Could it be that you became so accustomed to how you had to press the pedal on the old gummed-up system (with the worn out stretchy rubber hoses) that the system now just "seems" overly sensitive?

No. It's way too touchy. My friend drove it and made me glad I had my seat belt attached!

Wow! Testing the ol' inertial seat belts, are we?

It seems to me the only thing it could be is an over-active vacuum booster. How does it act if you disconnect and plug the manifold vacuum line?

Also, when you say you're adjusting the rod, are you talking about the rod between the pedal and the booster or between the booster and the master cylinder?

Whenever you replace the booster and/or the MC, I think it's good practice to compare the amount of rod protruding from the front of the booster and also the depth of the pocket in the backside of the MC against that of the original components. Both measurements would be made from a common booster/MC mating surface. (So if you have a spacer between the two components, you want to take that into account.) You have to do some mathematical adding and subtracting to verify you have replicated the original relationship between the two components. It's sounding like the rod on the front side of the booster may be set a bit too long???? That would be perfectly possible if it's a rebuilt and the rebuilder didn't have a clue where to set it, nor would they know how deep the pocket in the MC is.