Sinking brake pedal

2002 DODGE DURANGO
200 MILES • 4.7L • V8 • 4WD • AUTOMATIC
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WILLIAM MORRIS2
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  • 1 POST
Sinking brake pedal I replaced master cylinder and bled all brakes. I have vacuum on the check valve to the intake of I pull the valve out of the booster the pedal does not sink but as soon as I put the valve with vacuum back into the booster the pedal will sink. I pumped the brakes to empty vac and held my foot in the pedal and started car it does not indicate bad booster. help I am stumped. please.
Dec 30, 2016 at 11:19 AM
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CARADIODOC
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  • 34,308 POSTS
Forget the power booster. That has absolutely nothing to do with how far the brake pedal moves; only how easily it moves.

Do you have anti-lock brakes? If you do, there is a chance air got into the chambers in the hydraulic controller. You will need a scanner to command those valves to open so the air can be bled out.
Dec 30, 2016 at 2:30 PM
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STRAILER
  • CERTIFIED EXPERT
  • 53,855 POSTS
Hey,

Also check the caliper slides becasue if they are sticking it will cause the caliper to back up slightly giving you a low pedal.

Here is a guide on how to service the slides.

https://www.2carpros.com/articles/how-to-replace-front-brake-pads-and-rotors-fwd

Please let us know happens so it will help others.

Best, Ken
Dec 31, 2016 at 2:31 PM
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