lj2654 wrote:

I was wondering how to really know when to change an air filter on a CAT engine.

I have the vacuum gauge that is supposed to give you the info but how reliable are they?

The filter for my engine is a large canister that has to be changed out but its more awkward to do than hard.

I can remove the lower hose and visibly see it but that doesn't tell me anything!

DSDP Don wrote:

The absolute WORSE thing you can do to a diesel pusher air cleaner is to vacuum or blow it out with compressed air. You're taking a HUGE chance of moving the dust the filter captured to a place where it will be ingested and destroy your engine.

I give little or no value to the Air Minders. To me, they're totally useless. For the average guy doing 7500 miles a year, three years is a good change interval. We run between 10K - 15K a year and I change my filter every two years. My coach always performs well and I like keeping it that way. On one occasion, I bought two air cleaners because I got a good deal. This not a good idea, if you leave one setting for two years. Buy a fresh one when you're ready to change it out.

If yo own an expensive diesel pusher, don't cheapen out on maintenance.

larry cad wrote:

Several years ago, I realized my vacuum gage would show a clogged filter right after I would change the filter and put on a new one. I replaced the gage and got the same result. A couple of years ago I changed the filter and modified the intake to accept the next larger one. Gage hasn't acted up since. I suspect the factory specified the wrong one. BTW, I get slightly better fuel mileage since. Not much, but enough to make me happy I made the change.