Soft Brake pedal; not master cyl... help!

[jatzarik]

'02 Alero 2.2

Replaced brake hose on a hanging caliper. Then the brake pedal hits the floor way too easily.... more soft than spongy. It only does this with the power on. There are no leaks, either.

Replaced master cyl... still acts the same. Did a thorough bleed of all 4 lines at each wheel. Still no progress.

Dealer says it could be Brake Pressure Module or the lines may need to be pressure bled.

I am taking it to the mechanic but if anyone has any bright ideas that could save me some BIG, I'd appreciate it.

[danielsatur]

Start with the RR, LR, RF, than LF.

1) Pump the pedal 3X's, than hold break pedal 1/2 down.
2) Have a helper loosen the bleeder screw, the brake pedal should drop to the floor, keep the pedal to floor until the helper tightens the bleeder screw.
3) Repeat steps 1 & 2, until an even flow of brake fluid is comming out of bleeder screw.
4) Continue the bleeding process with the LR,RF, and LF.

Note - Check and keep the Master brake cylinder full of brake fluid.

[jatzarik]

did another bleed while car was running and did not get any progress. Is the suggestion above supposed to do something different than normal bleeding (which is essentially the same)?

[danielsatur]

It could be just alot of air, and pumping the breaks will help the hydraulic pressure blow out lines.

[Tony Silva]

BLEED THE BRAKE MASTER CYLINDER seperately and independantly from the brake lines...then bleed the lines...air can get trapped in the brake master cylinder and it could stay there for a long time till you create enough fluid turbulence within the master cylinder to force it into the lines, such as a quick, hard press of the brake pedal. Next, check the proportioning valve for damage or decay...then bleed brake lines as normal.