2012 Peterbilt 337 air brakes sticking...

What is the air pressure gauge saying? There is a primary and secondary air pressure on your dash. It has to be better than 60 PSI towards 120 or so. The more you got, they release. The less you have the more they stick.

Also where are you? 700 miles from CA dont seem like much but there is a current winter storm coming through, it's probably cold.

Getting after the slack adjusters is a sledgehammer to kill a church mouse. Something else is the problem I think.

Edit.

I worry that the spring brakes are doing exactly what they are supposed to do in low air pressure situation. And that crawling under there to release the pads with adjust the adjusters to take the parking off to make it move will turn that thing into a dangerous rammer killing people when you cannot stop.

 

Ok. I'll have to do some thinking Neighbor.

I am considering other parts of the truck but am not certain where the transmission has to say with the air braking system. One should not influence the other. I think somewhere you are out of adjustment on that truck either that or warped drums or bad pads or or or or. Makes my head spin.

Consider the air brake system it has two components. Service braking, parking braking (Also emergency low or no air supply braking via springs)

The transmission its supposed to be by itself. It can talk to the engine because it has to. Other than that it has no business talking to the air brake system.

If you are causing the truck to do things unnatural, then you have to think maybe something is getting crossed or shorted in your entire harness somewhere. That's a nightmare.

 

Most likely it does not have parking brakes on the front. You may have a sticking treadle valve (footvalve) which will put a little air to the system. When you crank it up in the morning take a air line off the front chamber and see if air is coming out of it. It it is there is your problem. If not that is the best I can tell without the truck.

 

That's beautiful. I had clean forgotten about that front end not having springs. *Bangs head. It makes perfect sense.

It goes to show don't rely on this old man and my outbursts online. It's really tough to see a problem without actually being there having lost half of my mind these days.

 

Hey I totally understand about the mind problem. I have that same occurring problem.

 

Steer axle or front drive? Does it have air on the service side air line when it does that?