Soft brake pedal after bleeding

FGR8FRK

MEMBER
1993 CHEVROLET SILVERADO
5.7L
V8
2WD
AUTOMATIC
226,000 MILES

Replaced rear brake shoes and cylinders after finding one cylinder leaking and the master cylinder dry, also ended up replacing both front calipers. Now after bleeding all four wheels (RR, LR, RF, LF) twice and getting solid fluid, the brake pedal seems to be way down with the motor running. When bleeding with the motor off it would pump up but if you wait about 30 seconds and push the pedal it goes down a bit but then pumping brings it back up.
Update: I have also now replaced the master cylinder, after bench bleeding it and installing, I have bled all four wheels twice and although it is a little better, the pedal still feels spongy.

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1 Reply

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

If the system drained, chances are the ABS module has air in it. What needs to be done is called an automated bleed. This is done with a scan tool capable of communicating with the ABS module. The only other thing that would cause a soft pedal would be if the rear brake shoes are out of adjustment.

Take a look at the directions below. They include how to perform the automated bleed procedure.

If your vehicle doesn't have ABS, let me know.

I hope this helps. Let me know if you have other questions and if this takes care of the problem.

Take care,

Joe

See pic below.

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