Yesterday, the brakes locked up on the truck several times. This was the first time in the 5,000-miles I've owned the truck that this has happened. The pavement was wet, but I've been on wet pavement plenty of times before. It also happened in more controlled situations today when I tried to make them lock up. Basically, it's an intermittent problem; I'll have them lock up at one intersection and work fine at the next. It happens in forward drive gears and in reverse.

There are no flashing yellow or red ABS lights on the dash; just the normal sequence when I turn on the key. I've grounded the ABS test lead and the yellow ABS light just stays on; no flashing or red lights or anything.

I've got the Ford service manuals and tried to read through them, but am over my head.

Anyone have this intermittent brake lockup problem? What did you do to diagnose and fix it?

Thanks,

Tom Herrick

 

i've had the same thing. ever figure this out?

 

Nope. It only happens when we have significant rain; and we've had a drought so it's been back-burnered.

Tom

 

There is only Rear ABS on these trucks. Was it only the rears that locked up?

 

You know, I'm not exactly sure how ABS works but. . .

in my old green F-150 one tire would constantly lock up if I braked to hard or quick. I had ABS in the rear, this was an 87. . .

It turns out one of the drums was soaked with oil from a leaking axle shaft seal. I don't know how or why it would have caused it too lock up on me, but after new shoes, scrubbing the drum, and fixing the leak it braked fine after wards. . .just my 2 cents

 

You are quite right. The Kelsey Hayes RABS used on these trucks is not much use. It only works if both rear wheels are locked so it is a must to have both rear brakes in good condition and both properly adjusted.