I cant get my brakes to work right. I have an awesome pedal when the engine is off. As soon as i start the car it drops to the floor. Master is new and properly bled, rear calipers are new and they are adjusted pretty well, and the booster is also new.

I dont get it. I plugged the lines to the master and it was fine on or off. I bled the poop out of the whole system. Went through approx a gallon of fluid.

What is causing my insanity?

 

Now i have replaced the prop valve with an adjustable one and put the front lines on a tee. Same problem. Is there different length pushrods for the booster by any chance?

 

If you pump the pedal with the car running does it slowly get hard?
What kind of vacuum are you making at idle at the booster.
does the check valve on the booster work?

 

It does not get harder. The check valve worked when removed from the 2000 suburban doner truck. As far as vacuum goes, i dont have a gauge but it is sucking quite well. i can see the hose suck in a bit but not suck closed.

 

The booster is bad. New or not.

 

I will get that warranteed as soon as it warms back up

 

Replaced booster again, and rear caliper for parking brake not returning properly. No change what so ever