Air Dryer

i have a 2004 pete 357 model, it’s a dump truck. My dryer continuously releases air from about 110psi till it reaches 125psi. I replaced the purge valve thinking it was the problem, it didn’t help. I went and bought a completely new dryer and it’s still having the same issue.

Does anyone have any suggestions what the issue is ?

 

Yes it is. I’ll check into that. Thank you

 

So I'm still having the issue after putting a new dryer, unloader valve and I also changed the inlet tube and hose because the hose itself wasn't looking good.

When I replaced the dryer there was a small black nipple screwed on where the purge valve is on the old dryer, I removed it and went to install into the new dryer but it seemed there was no threads for it. Inside that nipple theres a spring, do I need to tap those holes to install it ? does that spring actually do anything ?

 

I have replaced the governor and it’s mounted right next to the air dryer. I don’t have an actual picture of the whole dryer but this is what it’s like. There’s one picture of my actual governor and the other two are pictures I took of the internet. The one that has the circle in is where the spring is, it goes over top the purge.

 

So here are actual pictures of the dryer that’s on the truck. It’s the correct dryer as I got part number from peterbilt. I’ve changed just about everything, complete dryer, governor, unloader valve and inlet tube with hose. The other two pictures is the nipple and spring I was talking about, I took it off old dryer but on the new there’s holes for it but don’t have threads to be screwed in.

It’s an 04 Pete 357 with a C13.