Could a Code 4 (RABS Switch Valve Bad) cause slight to severe whell losk up. I've had the ABS light and P-Brake light coming on for some time now. Did a Brake job, alls new Drums/Shoes/Pads and Rotors. Calipers are the same, not leaking and seem to be going in and out. The only springs/hardware on the rear was new return springs.

What I'be still got is the lights coming on and now a lockup the other day that I fixed by re adjusting the drum, thought I had them too tight. It got me driving again.

But today I get home and noticed a slight drag and burning smell from the rear again, I am assuming I've come close to locking up again and plan on checking the rear drums and adjustment tommorrow.

Question is: Would a bad RABS Valve (Proportioning Valve) cause lock up... After the lights come on, which are not immediate but after about 5-10 minutes of driving, the pedal becomes harder at first push. I tested the RABS IAW the diagnostics that I've got with my FORD CD and I cannot get a resistance reading at all from the RABS Valve, am not sure if I;m testing correctly so I was gonna just pull it off and clean it up some before buying a $170 part.

Any Thoughts, expertise on testing RABS on F250

 

Fixed, believe the code. Bought a new RABS Valve (149 @ NAPA) and it's all fixed. Brakes work better than ever.

 

That's good news! Thanks for the follow-up...

 

Hello 1SG. I am having the same problem with my 93 F350 dullie. Did you find that the new RABS Valve did the trick in the long run. Any other problems after you posted that everything was working great.??? Any advice on changing the valve. thanks,

 

yeah it worked, bought mine from NAPA for 160.00. I took the old one in afterwards and got a 30 or 40 dollar core return on it. Brakes work a little better and the lights gone, no more locking up either. Some of my locking up problems were due to a rear brake not being together properly and the self-adjusting paw slipped down.

 

I called NAPA today and they said that they no longer have a vendor for that part. So i went to FORD and got a rebuilt one. $250. plus $100 core. It looks pretty easy to install. 1 plug, 2 lines, 3 bolts. Then just bleed the system. Any other advice or things I should be looking for when I do the install??? thanks,

 

I would check around, try a different NAPA. That is expensive, try CarQuest. And yeah it is simple.