Hi I drive a 2011 prostar cm-871 daycab . I was was droping a container at the port when It started that spitting air from bottom of the air dryer. It sounds like a rattle snake and it won't build up any air in the tanks but won't lose any either. It stops when I turn of the truck . I'm still there trying to fix this . Please any help would be very appreciated.
Thanks in advance.
if it has more than a few years on it and 600+k miles, I wouls suggest you replace the whole damn unit. the aluminum housing where the valve sits wears out too.
Possible governor, plastic check valve, or purge valve issue.
The truck has 400k but 14000 hours and it's up in Canada with all the salt in the winter . The valve cost 100$ and the unit about 400$. I bought the valve but my supposedly heavy duty pliers broke on me trying to remove the bad one . So I'm gonna return it and get the hole unit first thing in the morning. For 300$ more I guess it's worth not having to worry about that for awhile. Thanks guys
Mine did that once. Drain all of your air tanks...including the dryer reservoir tank. Turns out mine was full of water and slurry because dryer wasnt working. I did as rawze said, and replaced my whole unit with a bendix unit to include the reservoir.
Do yourself a favor and change the drain valves on all your tanks too.
I replace the entire air dryer every fall. You can get an AD-9 remanufactured one from Fort Garry or even Freightliner for under $200 exchanged with your old one.