Need some help diagnosing air bag problem. the bags only inflate a small amount, the truck frame isn't getting up off from the stops it rests on when the system is totally drained. The height adjusting arm and valve are intact, and not damaged. Truck will build air pressure as normal. Where to start looking? This is a low leaf Peterbilt suspension. Thanks for any help.
Is anything leaking? A big gash to an airbag won’t make noise. Check to see if the leveling valve is getting air.
I'll check things out tomorrow, in the daylight. Will post back if I find something. Thanks
Sometimes they install a valve on the air tank, that supplies air to the leveling valve. The little valve on the air tank opens around 65psi, delivering air to the inlet of the leveling valve. Sometimes that little valve gets plugged up or stuck and stops working. Just follow the leveling valve air supply line.
Pressure Protection valve that supplies air is rusted inside, very common. Air ride trailers have the same issue. Mounted on top of supply tank. Images of a two types, the Haldex is common on trailers and a piece of junk. *
Pressure protection valve and leveling valve checks out ok. There are three out of the four air bags are leaking! Guess that answers my problem......(should have checked them first) Thanks for your time everyone. Vernier
Alrighty then, we can wrap this one up. Thanks for the update Mr. Vernier. Be safe changing all those bags. Thanks Truck Shop for refreshing my memory on the Pressure Protection Valves. Let’s get that Pete back on the road, ASAP. If those wheels ain’t turnin’ we ain’t ernin’.
Ha Ha thanks Coaldust, the turnin part is ok . I don't know about the ernin part if fuel does what the prediction is to skyrocket this fall.