1998 379 air not building up

Did you replace the parts trying to fix the problem, or caused the problem after you replaced the parts?

 

you must find the air leak, air it up to 120psi {chock wheels} em. brakes off, have foot brake pushed full down, get out find leak with motor off.

 

It sounds like an air governor or air dryer problem. However, I would check the pressure release valves on your air tanks. You may want to get someone to listen while you work the brakes to see if they can hear the leak. When you changed out the air governor, did you make sure you plugged the right holes? Air dryers can also get grit in the valve that won't allow the air to build properly. It could be any number of things that are leaking. With that much of a leak it should not be too difficult to find. You may also want to check the pressure release valve, sometimes called a pop off valve on the air compressor. Good luck.

 

I agree, BD. The way it's worded leaves that in question.

 

I'm betting bad pancake in a brake chamber on one of the back axles.

 

what about the unloader in the top of compressor? a new kit cost about 15.00 & easy to put in. my first guess would be the blue air line going to trailer. along with the red line. since you already changed governor, if you find no leaks. unloader kit would be my next guess.

 

Sounds like a big leak in the brake circuit.

JMO