dahubby

Ive done all that i have found inthe forums. Here is my problem. When my car gets warm, the brake pedal gets hard and it engages both clipers. I have changed the Master cylinder, calipers, hoses, adjusted the brake switch etc. I pulled the exhaust hose out of the booster and the brake pedal released pressure. I am not sure what else to do. Any thoughts? Thanks for inputs...

dragon_lowrider

do you still have the vacuum check valve in the hose going to the booster from the manifold? other wise it sounds like your powerbooster is bad

MAD_MIKE

Exhaust?
You disconnected the main vacuum feed to the booster from the intake manifold and the pedal became easier?
Seems like there is an issue with your boosters internal check valve.

What does the pedal do after pumping it a few times when the car is off.
What happens when you rest your foot on the pedal and start the car?

dahubby

After i pump the pedal a few times it gets hard.when i start the car it softens up. after i start the car and i rest my foot on it it goes down half way, where it normally goes. When it warms up, it gets hard but its intermittent. Yes i still have the check valve installed.

I meant vacum, had a brain fart..

MAD_MIKE

If the pedal becomes hard, like when you bleed down the booster with the car off, there may be a problem with the booster. Recheck the main vacuum line to the booster, check the check valve is working(swap it out with a new or used one) and verify the engine is running normally when this occurs.

dahubby

i figured it out, it was the brake pedal switch. i guess it was adjusted to low..thanks for the help..