Soft brake pedal after bleeding

1993 CHEVROLET SILVERADO
226,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
Avatar
FGR8FRK
  • MEMBER
  • 51 POSTS
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.
Nov 28, 2021 at 8:05 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
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.
Nov 28, 2021 at 10:27 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.