Safarifriends.org

I was looking around for how often I should change my air filter given they are around $200 a whack now. Not sure if I can trust my visual filter indicator. “Spike45” (Gary) on IRV2.com is a retired CAT and Fleetguard field engineer spending close to 25 years in his field as a coolant specialist. While he has some excellent articles on coolant, his advice here seems sound.

https://www.irv2.com/forums/f115/what-s ... 95059.html

I’ll not paste his whole dissertation here since you can go to the link above for yourself but I’ll paste some interesting info from it here for your air filter edification…

“… most MH operations do not achieve sufficient run time and miles to bring on air filter plugging. If you check your restriction indicator, you may see little movement and conclude that it does not work. This is a common but unfortunate outcome even for large on-highway truck fleet operators who commonly put on 125,000 plus miles per year. For them, with their miles, they frequently change the air filter yearly, whether it is needed or not. For them, that works as they generally keep their units for 4 -5 years then trade them off.

For the MH operator a yearly air filter change is much less desirable as the miles involved are few. Air filters will pass dust when first installed. Usually, it will be during the first 25 hours of normal operation. New air filters are usually 99.3% efficient but after the initial 25 hours the efficiency goes up to 99.8%+ and remains for the duration until the 25 inch restriction limit is achieved. Fewer changes will equate to less dust ingested due to filter service. Any ingested dust is cumulative. Eventually, with enough changes the accumulated dust will reach 4 - 5 ounces, enough to cause cylinder bore and ring wear on a midrange size engine like a Cummins C, ISC, ISL, Caterpillar C9, C12 and comparable engines from International and Detroit.

My air filter was changed around 5K miles ago at the CAT dealership service department. All my trips were on interstate highways and paved campgrounds. I already have a Donaldson air filter on backorder for my CAT 3126B and I will tuck it away for some date far into the future. If anyone else is looking for non-China air filters for their rig, skip Amazon and hunt one down. These are getting difficult to find in stock including the WIX variation.

Yes, Cummins has been stating that in their manuals for many years. Change them only when the filter is full/restricted...

3 weeks later I am still waiting for my back ordered Donaldson CAT3126B air filter.

Interesting.

I read somewhere that every two years was suggested not because of plugging, but because of possible breakdown of the paper and glue in the element especially if it has ingested any water. Last time I swapped mine out it was probably 4-5 years old and looked just fine. Other than the expected amount of dust in the pleats, the glue and paper itself looked perfect. Indicator showed about half way to the red. In the future, at the 2 year mark, I'm temped to pull the inlet hose and inspect the visible pleats and glue, and if they look sound, close it back up and go another year then do the same again.

Yeah, I think the overarching message from those who seem to know a lot about it is that putting new one in frequently will cause the motor to ingest more dust until a certain point. Who would have figured that less is more in this case?

Quite a lot of the "how long between air filter changes" depends on a number of factors:

Drive in dusty conditions? Dirt roads?

Where is the air intake-- low and behind rear wheels? Up high where less dirt gets in?

Protection from water injection?

Said another way, there is no single "right answer".

But an emphatic DON'T: Never remove the filter and attempt to clean it. Way too easy to damage a pleat and dust your engine.

I'm pretty lucky. The original, owner had the air intake relocated to the side of the rear cap with a custom louvered intake cover. The old airbox is still there but abandoned. In seven years of ownership I've never seen evidence of water getting to the pleats although admittedly, we don't do much traveling in the rain. I remember reading a warning that removing the air filter and attempting to blow it out can be risky. Along with the chance of damaging the pleats, there's also the risk of moving dust from the outside to the inside of the filter. While not cheap, I figure if it's that it's money well spent to just replace it. An air filter is way cheaper than a dusted engine. One thing that's important in a replacement filter, regardless of the brand, is to make sure it's built with a metal screen on the inside of the pleats to help assure against paper getting ingested into the engine should the paper or glue fail.

It's good advice to occasionally reset the filter meter to see if it still works. I usually do it when doing an oil/fuel filter change.

Over changing air filters partly comes from people advertising a dirty air filter can hurt mileage and performance, so regular changes "help save fuel." That's only true when the filter has reached capacity or is contaminated. Years ago I stopped changing air filters with every oil change in my vehicles, going instead by a visual inspection. As you say, how often really depends on conditions. Because the area we lived in wasn't dusty, my air filters went quite a long time between changes. I also appreciate a service place inspecting them, but not automatically recommending that they be changed at each oil change.

They are not cheap now. Inflation and scarcity have made them double in price in the past couple of years. This is one "spare" item I carry with me as well as a regulator (thermostat) and a few other parts like old belts and hoses from previous preventive maintenance replacements. If you break down somewhere outside of a larger town or city and need one, good luck finding a place with one.

Well, the inflation factor has played a role in air filter prices for sure. Just checked the Napa Gold 6857 is now $355.99 for my '01 Zanzibar. That's an expensive "have one ready on hand" part.

Today, I did some digging and found that Wix filters has a cross reference for the Donaldson P537455 air filter for my coach. https://wixfilters.com/Lookup/PartDetai ... art=109436
It is much less than the Donaldson. It is $173 at rockauto.com. For that much difference, I think I can keep one at-the-ready.

chuckster wrote: ↑Wed Apr 10, 2024 1:06 pm Today, I did some digging and found that Wix filters has a cross reference for the Donaldson P537455 air filter for my coach. https://wixfilters.com/Lookup/PartDetai ... art=109436
It is much less than the Donaldson. It is $173 at rockauto.com. For that much difference, I think I can keep one at-the-ready.

Wix does make quality filters-- no worries.

BUT, I would not buy one ahead and store it. All filters age (paper/glue, etc). Fresh is good.