OK I rebuilt my brakes about 6 mouth ago and the rear brakes have started to lockup. I am thinking its the RWAL that is the trouble. is it worth putting any time into the RWAL or just bypass it. it stated out locking once in a while now its do it most of the time. when i did the brakes I put the 1ton wheel cly. and the 3" shoes on it with all new springs and one new drum. Thank you Ken

 

What are you working on? I put the 1989 Chevy 1 ton wheel cylinders on my dually and haven't experienced a problem. IMHO RAWL is a very good thing when it is right. If it was mine, I would replace the RAWL valve and get the system working.

 

Truck is a 92 d250 Ken

 

Have you tried pulling out the codes off the computer? There are a few things to look at. The sensing wire going to the rear end, did you flush all the old nasty brake fluid out of the lines when you did the brakes?

 

I'd byapss the RWAL, and back the rear brakes off just a hair til it brakes like you like. If it locks up on gravel, that is normal, but it will also likely lockup on wet streets, too. Ice is a given.....

 

If they are locking up you probably have a leaky wheel seal.

 

Also at the time I did the brakes I flushed the system. new shoes, new wheel cylinders, new hoses,one new drum,new springs,new adjusters,new bearings,sleeve's on the hubs,the only thing I dint work on is the RWAL system Ken

 

Dont you have to bleed the RWAL also? I thought there was something up on the frame by the fuel tank.

 

One side or both ??

This probably isn't your situation, but :

I had a wheel on one of my goose-necks that would lock up at the least excuse; it has the same hubs/brakes as the rears on these trucks.

After exhausting all possibles, I found that the leading edge on one of the shoes was slightly bent.

I straightened the shoe and no more lock-up.

 

YES. drove me nuts figuring out why I couldn't get rear brakes when I bought it. When I discovered this I had more issues because the bleed screw was clogged, so when I cracked it I got nothing from there either!! And the little screw in there is DIFFERENT than the ones on the wheel cylinders. It's a 5/16" wrench vs a 3/8" on the wheel cylinders, and I think the threads are different too.

Bleed the RWAL first, then the driver side, then the passenger side