Brake Issue

[midrange]

My buddy has a 1992 Tempo.

My brakes went all soft so we did a brake job. We put new calipers, rotors, and pads at the front and the rears seem to be passable. We bled all 4 corners.

With the car off, if you pump the peddle it gets a little stiffer. And when you pump it up and hold, i can't turn the wheels.

When you start it, the brake goes very soft and we lose brakes.

Is this a brake booster or master problem?

[Davescort97]

It could be the brake booster. A tear in the diaphragm could cause this. If the engine sounds different up depressing the brake this is the problem. I do think that it is the master cylinder or air in the lines. When you bled the system on all 4 corners, did you start with the wheel farthest from the master and work your way to the shortest? I do think it is the master if all of the air is out of the lines. You can bleed the master on the vehicle by cracking one of the brake lines and have somebody operate the brake pedal.

[midrange]

yeah we def did that. The engine does change when you push brake peddle. Also when the engine is running, when you push the brake peddle, not only does it change the idle of the egine, but it sounds like air is being pushed out somewhere when you push the brakes.. Kinda like a noise when you squeeze a ball that deflates.

[rhandwor]

Normally a leaking brake booster will cause problems with the idle. If this is the case disconnect and install a plug in the vacuum hose. If this smooths out the engine buy a rebuilt unit.

[plymouthsrock]

Sounds to me like master or air on the lines. Boosters failing usually results in a hard pedal condition, or dragging brakes.