Pete 379 Brakes are stuck

Thank you!! The problem has to be at the brake pedal or possibly in the valve/s , other than that i got nothing! BTW instead of unhooking the batteries it would've been easy and faster to pull the fuse.

 

I'm interested in this and hope the hope the Op comes back and fills us in

 

I had the same issue a few weeks ago while in Dallas.
When I parked all was well. The next morning I pre-tripped just fine, but when I hit the brakes I noticed that they stayed partially engaged.
The cylinder in the treadle valve was not returning all the way up. I considered dragging brakes into the TA shop, but first walked over to check the price of a new valve.
After getting the price and "can't get one until morning", I went back to the truck cussing. A Pete driver next to me walked over with a pair of channel locks and WD40.
Few squirts of WD40 and a little twist on the cylinder top(under the pedal) and the brakes unstuck. I worked with it a while longer until it was moving smooth.

There was a build-up of unknown-crap/crud around the cylinder that was catching its movement. Once that was clean, the valve operated normally.
I replaced the valve later, but the one taken out was operating as well as the new one and the shop took it apart and couldnt tell there was ever a problem other than channel-lock marks at the top edge of the cylinder.

Now I added a pocket-sized WD40 can + channel-locks to my glove box tool collection

 

Yup, same problem here. Checked everything else except the pedal. Mine was really stuck down because it hadn't moved in a month and a bunch of crud got down into the top of the valve. I need to find another rubber seal to help prevent it from happening again.

 

I just had the same exact problem with mine to a "T"! Called the Pete shop and told me exactly what many of you have said "crud/corrosion around the plunger under the pedal". They did suggest also to use a wire brush to remove any unseen debris around the plunger and aluminum casting it slides in and out of. Also to vacuum the debris/crud under and around the pedal as well as washing out the boot. Once all was clean they also suggested anti-seize be applied to the plunger. I'm still in the process of cleaning it up but the plunger is all the way up with no application pressure and lights are off.

Thank all of you even though it's an old thread I didn't think about the brake pedal until after reading what you've wrote. I hope all this will help another driver too as it's an easy fix that could be costly if you don't do the work yourself.

 

Sounds weird, after being parked a long time and a brake won't release, try this. Release the brakes then dump the air bags then put air back in the bags. Away you go.

 

Had the same scenario on my 389 log truck and the pedal was very hard to push. Almost had to stomp to get any brakes. When I got the pin out, the bottom of the pedal and foot valve plunger were packed solid with dried mud. Got it all vacuumed out and used white pith lube on the plunger. Left it overnight and brakes are easier than my Silverado’s.