Power brake adjustment

[dab67]

Ok what do I need to adjust or change,,,,,,,,,,,, The first time I drive my car and I step on the power brakes, they grab so hard they almost put you through the front window. After that initial braking they begin to adjust are fine after about the 3rd or 4th stop. What causes this? air? unbalanced action from the front power brakes and the back brakes? wrong size brake booster? I have a 9" booster or how about a bad power brake master cylinder? Or none of the above!!!!!!!!!!!!!!!

Dave

[GaryL]

Too much pressure to the front brakes. What is your setup? factory or after-market.

[JohnZ]

That's frequently a classic symptom of the front system metering valve (the round one below the master cylinder) being stuck open, which causes the front brakes to engage before there's any engagement at all of the rear drums. That valve (when it's working) doesn't allow any fluid displacement in the front system until the rears see 30-40 psi, to get the rear shoes out to the drums for a balanced application.

[Charley]

That's frequently a classic symptom of the front system metering valve (the round one below the master cylinder) being stuck open, which causes the front brakes to engage before there's any engagement at all of the rear drums. That valve (when it's working) doesn't allow any fluid displacement in the front system until the rears see 30-40 psi, to get the rear shoes out to the drums for a balanced application.

..........  I did not know that....Cool.

[dab67]

Gary:

As far as I know, they are factory pb.

JonhZ: Thanks for the info on where to look!!!!!!!! As usual, CRG comes through again. I will check the valve and see what is happening. I presume  I can change the valve correct?

Dave

[JohnZ]

Gary:

As far as I know, they are factory pb.

JonhZ: Thanks for the info on where to look!!!!!!!! As usual, CRG comes through again. I will check the valve and see what is happening. I presume  I can change the valve correct?

Dave

New reproductions of the metering valve are now available, and an outfit in California called "Karp's Brake" can rebuild them - see the "Brakes and Suspension" section at www.camaros.net. Heartbeat City has a rebuild kit, but I'm not sure if it has one of the internal cup seals.

[GaryL]

I got my metering valve (the round one) done by Karp's Brake in So. Cal. (909)985-0800 for $65. A note, the rubber cover on the button is not reproduced, at least that is what Karp's told me. Brakebooster.com did my booster and metering valve bracket. Very nice in gold zinc