Mechanics

BRAKE PEDAL GOES TO THE FLOOR WHILE APPLYING BRAKES SLOWLY.

2003 Ford F-150 • 145,000 miles

Starting out I have a brake pedal that stops the truck, but when I sit at a light the brake pedal does all the way to the floor and the truck inches forward. The master cylinder has been replaced to try and correct the issue, all four wheel seals were checked and no leaks found, all brake lines were bled and have no leaks and the brake fluid stays at the proper level, so the system does not have a leak. Could the ABS box be the issue and what in the ABS box would cause this problem?
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Mbuckhan
September 10, 2013.



It can take up to 3 qts to bleed brakes on an abs system was the master bled prior to installation? If not that is your problem you'll need to bleed again preferably with a power bleeder or vacuum. Here is a test to do on abs unit.

Probably abs hydraulic unit. If it is 2wal you should find a rubber cap on one end of the release valve. Take the cap off and stick a straightened paper clip in the hole. Have someone push on the brakes, if it pushes your paper clip then the 2wal valve is bad. Good luck


Hmac300
Sep 10, 2013.
THE OLE MASTER CYLINDER COULD HAVE A SO CALLED "INTERNAL LEAK", WHEREAS THE PLUNGER INSIDE IS NOT SEALING IN THE BORE 100%. FLUID SLOWLY LEAKS BY. THIS CAN HAPPEN EVEN WITH A BRAND NEW UNIT

REBUILDING OR REPLACING THE MASTER CYLINDER IS THE FIX

THE MEDIC

well over 7000 answers thrown out there!


Tiny
CJ MEDEVAC
Sep 21, 2013.