Bendix purge valve ?

[Geared_Cortex]

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.

[Rawze]

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.

[kmk]

Possible governor, plastic check valve, or purge valve issue.

[Geared_Cortex]

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

[dhirocz]

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.

[uncleal13]

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.