BUS air cycles between 120 & 114

[Catskinner!]

Bob

The spitter valve is the discharge valve on the air dryer
that {spits} moisture and air when the governor unloads
the compressor.

Catskinner!

[gumpy]

The mfg calls it a purge valve.

[Prather]

It was the AD-2 dryer, specifically the dryer outlet check valve was leaking.

When the AD-2 dryer was installed, the original 3/4 inch check valve at the wet tank inlet had been removed I guess. Had that check valve remained in the system, doubt I would have had seen the problem.  Since decicant replacement was about due any way just replaced dryer.  Everything working fine now.

Thanks for all the input.

Prather

[gumpy]

Good deal! 

Chalk that one up to TomC, and I learned something new 

Thanks for posting the solution.