Air Filter Maintance

[riverman]

Thanks for this great site.

I did see what I consider an error on the home page maintenance.

NEVER use an air compressor to blow out an air filter. Tapping it is ok. The max design capacity of an air filters would be a delta p of 14 psi (the max pressure that an engine would ever see and it would never reach this because engine will never be a perfect vacuum). If you hit it with shop air at 100 psi or higher you can create microscopic tears in element, and then dust your engine.

 

[Bulldog]

That's why I replace mine every oil change. A air filter is much cheaper than taking a chance on a engine.

 

[riverman]

Here is something to toss out...is a partially restricted air filter better at filtering (disregard flow rate because engineers design engines to run in real world situations) then a new one?

 

[ipz2222]

No, a used filter does not filter better. The smallest filter holes are allready stopped up, all that's left is the larger holes, more stuff getting thru.

 

[TripleR]

My manuals indicate it is OK to blow filters out and give the pressure not to exceed.

 

[riverman]

Wow!! Is that the factory manual?

I read an artical once...a cement saw builder stated that it is better to have a dirty filter until the performace decreases.

 

[skeets]

WOW ya mean my K&N filters are a scam????

 

[Bulldog]

It's hard to compair a K&N to a paper filter.

 

[TripleR]

Wow!! Is that the factory manual?

I read an artical once...a cement saw builder stated that it is better to have a dirty filter until the performace decreases.

Yeah, my owner's manuals.

 

[meanjean]

I washed semi trucks as one of my first gigs.
A mechanic was blowing out an air filter with an air hose...bad idea.
The shop foreman came over and grabbed the filter and booted it across the shop and shouted at him...

"You effin dummie, you might as well throw a handful of sand and $hit into the engine. Replace the GD air filter and be done with it!"

I've never used compressed air to clean an air filter and never will.
You loosen up the small particles which have been trapped and you run the risk of adding tears/holes to the filter thus rendering it useless.

Never use compressed air.

 

[skeets]

I dont know if its any different than blowing them out but back as a kid and bucks were really tight I used Moms vaccume sweeper with that little brush attchemnt so suck the dirt off the out side of the filter, but then motors didnt last real long any way,, Ya can only pull so many 6 grand hole shots afor stuff breaks,,lol

 

[moog]

A dirty filter does filter more efficiently than a clean one. The problem is that after they get so dirty ie. so efficient, they don't allow the proper air flow which causes other problems. For example, on your home furnace a dirty filter will cause your furnace to run longer and use more gas/oil etc. Under extreme circumstances it can cause cracks in the heat exchangers which can allow carbon monoxide into your living space. If your trying to run your air conditioner and your filters are dirty after a certain point your a/c evaporator will freeze.

The "bigger" holes someone mentioned allows the same small particles through whether the air filter is clean or dirty, the only difference being the velocity at which those small particles go through the "bigger" holes. That being said, the reality is those "bigger" holes get filled up as the filter gets dirtier which in turn causes them to catch smaller and smaller particles until no air at all can be pulled through the filter.

 

[riverman]

My point with bringing this up, is that we all love our Kubota(s) and it would be best if blowing filter out is removed from the recommended maintenance because it is a bad practice.

 

[91redfrod]

I'm glad to read this as a new to me tractor owner i have been going through my B7200 and hav'nt done anything to the air filter yet, i will replace it and get back to work. The air filters i use compressed air to clean would be the chain saw & the weed eater, as for the cars & trucks it's replace & toss.

 

[Stubbyie]

There's a difference between 'selling' air filters and the engineers that 'designed' the air filter.

I have some experience in filtering for industrial processes.

Engineers will talk about "over-filtering"--changing out filters too often. The ideal filtering condition is after the new filter is 'charged' with a preload. New filters let through too much material until they achieve their initial design loading.

NEVER use compressed air to clean a filter. If you just have to do something, tap it gently on hard surface, wipe clean the gaskets, and reinstall. I'd be reluctant to use shop vac for concern of damaging element as particles are moved around and through from one side to the other.

Filters are cheap. Run them long, then buy new.

 

[TripleR]

Yeah, surely the engineers working in a company that has been in business since 1890 and spends millions if not billions of dollars in R&D each year should know better, if only they would get on the Internet more often it would save them a lot of money.

 

[riverman]

In my experience, the engineers are not the ones writing the owners manuals you are reading(in fact, I can guaranteeing you that engine designer did not write the owners manual and it is unlikely they even had it cross their desk for approval<AKA "No need for red stamp">) and it is someone in the USA that takes Janglish and rewrites it...and they could be an office dweller that does not live in the real world. Sometimes the writer can copy and paste the text from other manuals (this could have been left over from a foam filter or the oil bath) and never question if it is best practice.

I have seen maintenance in manuals from major manufacturers that refer practices that are no longer needed because of changes that are 10+ years out of production.

I can assure you that blowing a filter out is a very bad idea because the risk is too great. If the filter is marginal tap it out and get a new one on the way as soon as possible. I can also assure you that Kubota will not fix your engine if you blow out the filter and cause tears leading to an engine failure.

IMHO this form should be about best practices, not a bad idea that is in print from the factory.

However, rebuilding tractor engines is a hobby of mine (therapy actually) and if people want to wreck tractors, I am always looking for another project!