1995 Chevy Cavalier 4 cyl Front Wheel Drive Manual 145k miles
I have a 1995 cavalier z24, When I drive the car for about 5 - 10 mins normal driving, the brake pedal starts to build up pressure and get hard, I took the car to a mechanic to see what was wrong and they told me it would either be the calipers were bad or there a brake hose was colapsing, I changed the calipers and the brakes hoses on the front, and the brakes still lock up and get really hot and theres still the hard pedal? What else could it be? The car was wrecked a few months back and most of the front was rebuilt, it has a new master cylinder, what could be wrong?
HARD BRAKE PEDAL Lack of power assist may be due to low engine vacuum, a leaky vacuum hose or a defective booster. Sometimes a faulty check valve will allow vacuum to bleed out of the booster causing a hard pedal when the brakes are applied. This condition can be diagnosed by starting the engine (to build vacuum), shutting it off, waiting four or five minutes, then trying the brakes to see if there is power assist. No assist means a new check valve is needed.
A quick way to check the vacuum booster is to pump the brake pedal several times with the engine off to bleed off any vacuum that may still be in the unit. Then hold your foot on the pedal and start the engine. If the booster is working, the amount of effort required to hold the pedal should drop and the pedal itself may depress slightly. If nothing happens and the vacuum connections to the booster unit are okay, a new booster is needed (the vacuum hose should be replaced, too).