1999 Chevy Suburban low brake pedal

Tiny
ACE58
  • MEMBER
  • 1999 CHEVROLET SUBURBAN
I had a rear wheel cylinder seal failure. The pedal dropped down, the dashboard brake light came on, but I still had front brakes. I decided to convert to rear disc brakes instead of repairing existing drum set up, with a complete kit from EGR. I continued to drive the vehicle, on a limited basis, until the parts arrived, adding fluid as necessary. I installed the complete kit and bled all 4 calipers. I still have a low pedal, and the brake light is still on. How can I remedy situation? Thanks
Wednesday, July 30th, 2008 AT 9:18 PM

7 Replies

Tiny
BLACKOP555
  • MECHANIC
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If the fluid got too low it could be that youve gotten air in the master cylinder and it will have to be bench bled before anything else can commence

will pedal get hard with key off even a slight bit harder.
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Monday, March 15th, 2021 AT 11:46 AM
Tiny
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Yes, it is marginally better with key off.

I bled lines at master cylinder and at each wheel, left rear-left front-right rear-right front, with no improvement in pedal or elimination of light on dash
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Monday, March 15th, 2021 AT 11:46 AM
Tiny
BLACKOP555
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Pump it up the pedal till its hard. From there push about 200 pounds of force on the pedal and hold it, does pedal stay or does it continue to sink lower, if it goes down master cylinder may be leaking internally.
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Monday, March 15th, 2021 AT 11:46 AM
Tiny
ACE58
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With the hydra-boost, the pedal doesn't pump up but, it does maintain a constant level, although quite low. While running, the same level is maintained and when "200 pounds pressure" is applied the front wheels lock up. The rear discs stay cool indicating they are not working.

A friend said an air bubble in the ABS could cause a problem but, wouldn't air be eliminated through bleeding? Thanks for your help.
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Monday, March 15th, 2021 AT 11:46 AM
Tiny
BLACKOP555
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I was saying put on the pressure so if it goes down then your loosing brake fluid through a leak causing the pedal to be low.

Air can cause a low pedal, but abs has to be bleed with a scan tool not the conventional techniques.
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Monday, March 15th, 2021 AT 11:46 AM
Tiny
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Thanks for reply. Been away. What type of scan tool is used for ABS brake bleeding? Is this a dealer only tool?
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Monday, March 15th, 2021 AT 11:46 AM
Tiny
BLACKOP555
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For the price it might as well be
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Monday, March 15th, 2021 AT 11:46 AM

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