To oil or not oil OPE foam pre-filters

[92saturnsl2]

Most of my OPE has a air filter with a foam pre-filter element that goes around or on top of it. This includes my Echo trimmer, two Kohler Command V-twins, Briggs 900-series on my tiller, and a couple others.

In the past I have always squeezed some oil into the filter (usually using MMO or something light viscosity that spreads evenly) before installing it. But I've also noticed that when doing this, the pre-filters get gummed up with crap quickly, I can't even get a mowing season out of them before having to replace or clean the pre-filter. Hard to clean all the gunk out and for the price they usually just get replaced.

Is there any benefit to oiling the pre-filter, or should I just let it be? What do you guys do?

 

[Chris142]

Afik foam filters are oiled.

 

[oldhp]

Isn't that the purpose of the pre-filter? I would just keep it oiled as you have been doing. Otherwise your regular filters are going to get dirty faster. I put the filter under water and squeeze Dawn into it. I keep squeezing and rinsing until it rinses clean water. When dry, I've used everything from engine oil to WD-40, doesn't seem to make a difference.

 

[Dinoburner]

Leaving the pre filter dry allows for better air flow longer but of coarse fills the secondary quicker with the finer particles. We keep the pre clean and change both yearly.

 

[Linctex]

I always oil mine very lightly... a little goes a long way

Just dawn dish soap and water cleans them up fine. Don't try to get it 100% clean again - that's fruitless.

 

[AnthemBassMan]

My Mother-in-law's John Deere x475 tractor manual says NOT to oil the foam ore-filter. But I do oil the don filters on my Lawn Boys and weed eater. Also on the usual Briggs vertical mower engines.

L8R,
Matt

 

[Kira]

Running water and repeatedly squeezing Dawn dishwashing liquid through it.....

DON'T DO IT IF YOU HAVE A SEPTIC SYSTEM.

For the waste made, it mightn't be a good idea for municipal sewage systems either. Why tax the devil out of them?

 

[ragtoplvr]

Originally Posted by AnthemBassMan
My Mother-in-law's John Deere x475 tractor manual says NOT to oil the foam ore-filter. But I do oil the don filters on my Lawn Boys and weed eater. Also on the usual Briggs vertical mower engines.

L8R,
Matt

There is enough spit back before the reeds close that a lawboy filter is automatically oiled.

Rod

 

[dwendt44]

Quote
My Mother-in-law's John Deere x475 tractor manual says NOT to oil the foam ore-filter.


Perhaps because some folks overdo the oil and it drips onto the paper filter element below, causing
it to deteriorate.

I lightly spray the foam with WD-40 let it air dry for a bit before re-installing the foam pre-filter.


My 2¢

 

[HM12460]

I oil mine lightly and squeeze out the excess. They clean well with some hot water and Dawn dish soap.

 

[meep]

I'd oil it unless the manual says not to. If I didn't have a manual, I'd oil it but would take extra care to make sure it was light and not heavy.

 

[bchannell]

I used to oil the pre-filter on my JD 425, but lately have been just cleaning and using it dry. It still catches the boulders headed into the filter, and doesn't clog up so fast. I have to clean it out a little bit sooner, but it's a whole lot easier. I've had some trouble with the filter clogging up and the tractor running rich, so I made the switch. I also hear that JD and Kubota has changed their minds on the issue and now recommend not oiling so I'm ok with that.

 

[Clayslayer]

I always oil foam filters. I bought a quart of TwinAir filter oil several years ago for the UNI filter in my ATV. I don't think my grandchildren will ever finish off that quart of oil.... little goes a long way. For what it's worth: I put the filter in a zip lock bag, pour in a little oil, then squish the filter around until it's all the same color and adding oil if needed. Filter oil is....sticky. Very sticky. K&N filter oil works well too. Same stuff really...just red instead of blue.

 

[nomas]

My Kohler engine on my Bad Boy mower has a foam prefilter . I never even checked the manual , I just wash and oil it every couple of mowings . It's pretty dirty which shows it's doing it's job .

 

[mr_diy]

My John Deere 170 manual says after cleaning to use motor oil on the pre-filter, approximately 1 oz. I used some K&N filter oil I had and put drops all over and wearing a glove squeezed the foam to work the oil around for even coverage. I'm sure the paper filter will absorb some oil but minor.

The air cleaner label says the paper element can also be washed, but water would not flow through the paper so it did not seem to do much cleaning. Vacuum with brush attachment also did not remove debris that was deep in the pleats. Removed some of this with a tooth pick and tapping filter on hard surface.

 

[MParr]

The foam prefilter is supposed to be oiled. Kohler says to wash them in soap and water every 25 hours. Rinse them and let them dry thoroughly. After they dry, spray lightly with a foam filter oil of your choice.

 

[slomo]

Running water and repeatedly squeezing Dawn dishwashing liquid through it.....

DON'T DO IT IF YOU HAVE A SEPTIC SYSTEM.

For the waste made, it mightn't be a good idea for municipal sewage systems either. Why tax the devil out of them?

Explain your statement please.

Now if we were talking bleach and a septic, I would agree.

 

[slomo]

My ? is why not oil it? We all know it aids in catching grit from entering the engine. That is the job of a filter. Filters are much cheaper than a new engine.

On filters that have a rubber outer around the paper, I put a line of grease on the rubber. Do all I can to stop grit from getting past the filter. Most filters even OEM's don't fit the airbox 100% air/dirt tight.

 

[Kira]

We grew up in an old house with a shallow well and an undersized septic system.
We never cleaned paint brushes or used lots of detergents for fear of killing the biology of the system.

If we , now I, am overcautious, then the joke's on me. Do you know septic systems?

If you do I have a question. Does raw hamburger meat contain enough microbial activity to populate a septic tank?
We always used Rid-X. I also added 10 ponds of white sugar a friend gave me. It had been water damaged and needed to be dissolved first.

 

[Brian123]

I did it a few times, adding oil to the pre filter, ended up with a nice yellow oil stain on the air filter. So I put on a new air filter and a member here recommended that I should not oil the pre foam filter. Now the riding mower is blowing fuses. LOL