[Roscoeapproved]

There are so many factors that determine the life of the air dryer the safest way to make sure it is doing its job is to pick an interval based on miles or time that works and stick to it. Good filters with life remaining will be discarded, but the items easily affected my moisture will be safe.

As miles accumulate or oil passes the element into the wet tank the interval needs to be changed or the compressor replaced.

Most owners however fail to insure the shitty air / water separator for the aux compressor is a serious entry point for moisture into the accessory tank.

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Jeff and Lindsay

91 Marathon XL

[Dick]

The first things downstream from my 120vac aux system air compressor are 2 SMC brand, model AMG-150C-N02BC, water air separators. They do a good job keeping moisture out of the aux air system. They each have a sight glass, a float type automatic drain, and a mechanical drain. Here’s a SMC pdf link: http://www.smcpneumatics.com/pdfs/AM_AFF.pdf

Its been yrs since I’ve been inside of one of the SMC separators to check tem out. Recently I opened them up and can report that all is well. Filters didn’t need changing. Minimal signs of ever having much moisture in them.

I minimize aux compressor use. The only item we need it for is to keep the gen minbags aired up when dry camping and to air the belt tensioiners a little before starting the Detroit to travel. My aux system leak rate is about 10 psi/hr.

3 yrs ago I removed the little Norgren air/water separator that Liberty had installed downstream of all the air suspension components. The Norgren never caught an moisture. So out of curiosity I installed in its place a Wix ACK10 spin on water filter kit.

Recently I cut it open and after 3 yrs of use it looks like new. So that was a waste.

I drain the 4 air tanks (wet, primary, secondary, and aux) at least annually. The only moisture I’ve ever seen is a drop or 2 of oil out of the wet tank.