[Archived]

I won’t say that is a trick question, but it is one in which there are multiple correct answers.

I use a Norgren water trap one the line from the aux. compressor and ahead of everything else. The line from my aux compressor first goes through a small copper tube coil to reduce the air temp, then about 15 feet of air line where it cools further, then into the trap. I have to drain the trap every 4 days to a week when we are in an area of high humidity because my aux compressor runs about a minute every 2 to 3 hours.

But I could trap moisture just as easily in a small air tank, with a drain in the bottom and air in and out at the top, two separate fittings.

I think some coaches have been equipped with air dryers, such as miniature versions of the air dryer installed on the chassis. If you do add a moisture trap of some sort plan on doing some plumbing work. FWIW, if you keep the chassis air dryer maintained, and periodically drain all OEM air tanks your accessory air will be dry and all you need to do is to make sure the compressed air from the aux compressor is equally dry so be certain that pressurized air is dried before it goes anywhere else.

[John]

Here is a thread I started on this subject with pics

SMC Air Filter thread

[Jerry]

Jeff, my accessory air compressor has an aluminum tank that does a good job at cooling the compressed air and collecting moisture at the bottom of the tank.

Just to be cautious, I (ETLC) added a Norgren filter/moisture separator to the outlet of the tank (not the compressor).

After our recent 6 weeks trip, I drained the tank and got just a very small amount of water, maybe a milliliter or two.

I then drained the Norgren filter/dryer and got nothing… totally dry.

The aluminum tank obviously does a good job in cooling the compressed air and collecting any moisture. I know your setup is different but the need remains the same

FYI… my accessory compressor runs once every 3-4 days when I’m parked… (smile)

[Andy]

Are these units in steer compartment?

[Deleted User]

Mine is but I’ve seen some in the generator bay. Very converter specific.