First, this truck doesn't get driven a lot. After spending 4 weeks in the hospital and 3 weeks recovering before I could drive, I discovered that the brakes were gone on my old F150. Given my physical condition at the moment, doing a repair myself was not in the cards; so I took it over to my favorite shop. They did a number on it replacing the master cylinder and a long list of things. When I picked it up, I noticed that it would not free-wheel in reverse after depressing the clutch; so I left it for another couple days. I picked it up yesterday and it seemed OK in the lot, but when I hit the brakes because someone stopped short in front of me, the rear brakes locked up again.

I had to drive about another mile with the brakes locked. The shop will take care of anything that got damaged from the heat (warped drums, new shoes . . . whatever). Is there anything about the brakes in a 21 year old F150 that would be different enough that a modern mechanic might not be familiar with them? I'm not trying to tell them how to do their job. (If I didn't trust them, I'd find another shop.) I'm just trying to find out if there is anything about the braking system that I might suggest they take a look at.

I did a search here and found one thread discussing a right rear brake lockup. I didn't see a resolution posted, but I did see a recommendation to check the pressure equalization valve in the master cylinder that controls pressure between front and rear wheels. There were the expected cautions to check springs, wheel cylinders, etc. which I have been told has already been done. Another thing I noticed is that depressing the foot pedal on the emergency brake gives no resistance and the pedal goes all the way down (this with the rear brakes locked). Does this symptom point to anything I should suggest?

Would appreciate any information you could give me about this brake system specifically or other things to check on any older model brakes.

 

Your RABS valve is probably plugged up. When you step on the pedal, it forces fluid through the valve and engages the shoes. The springs aren't strong enough to overcome the blockage so they stay engaged for a while. You'll probably notice that if you let it sit for a while the brakes will release.

It also sounds like you either have a broken e-brake cable, the cable is disconnected at the shoe, or some other problem.

To be honest, a competent garage wouldn't let a vehicle out the door with a broken e-brake. I would not trust this shop.

 

Thanks for the input, Andy!

The e-brake cable has been checked and no problems were found.

Is the RABS valve located near the master cylinder? I've not personally done a brake job is probably 25 years plus I know very little about this F150.

Thanks again for the information.

 

The RABS module is located on the driver side frame rail.

 

Thanks, xdevdogx!

I'm leavin' the replacement up to the garage.

Thanks again!