Rear brakes not working
 

2005 Excursion 6.0


Just noticed that the rears discs are rusty and pitted, after just completing a 500 mile road trip... They obviously haven't been working for a while.
Funny but I never noticed the loss of stopping power. I guess the front brakes do most of the work anyway.


It seems odd that BOTH rear brakes stopped working (I assume at the same time). If one caliper froze up, I could see it, but both calipers froze at the same time?


Is there anything else in the braking system that could cause both rear brakes to stop working? ... like maybe a stuck bias valve, or shuttle valve?


Appreciate any help............

Rear brakes on these trucks do about 40-45% of the braking. There is no bias or shuttle valves in the hydraulics other then the ABS trying to stop skidding wheels. The shared item with the channel for both rear brakesother then the master cylinder is the ABS controller and the rear brake drop line between the frame and the axle. The possibility of both rear brakes freezing up at the same time is not as remote as you think; Sliding pins, caliper pistons, rear caliper hoses, pads in bracket are all common issues.