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Do you safety your oil filter?

Rick_A

Well Known Member
The thread about re-useable oil filters got me thinking about the practice of using safety wire on the oil filter and if it is really necessary.

I use to do it all the time but I rarely do it any more. It seems like a waste of time and effort. It always takes a lot of force to loosen a filter that has been torqued to 15 ft lbs.

Is this just a out dated practice that's done because "it's the way it's always been done"? Maybe it dates back to a time when filters were more apt to loosen on their own?

(I was going to create a poll but couldn't figure out how to do it)
 
I always safety wire the oil filter. AFAIK, it's still considered "best practice" in the aviation maintenance world. I'm not near expert enough to know whether or not it's necessary, but I try to be careful to not let the "Experimental" category lead me to cut corners and deviate from accepted safety practice.
 
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16-18 ft/lbs is the correct #.
I safety customers filters so they don't freak out, but not my own. :eek:
I suspect some folks may not want to publicize their use of 'non-standard' practices, however the latest "trend" of using 'non-approved' cleanable filters makes it irrelevant, I guess?
 
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This comes up from time to time. It seems that at least one helicopter manufacturer no longer recommends safety wire on the oil filter.

It's pretty easy to do, adding about 2 mins to the oil change process. I'm not really seeing a downside, but I've never read a crash report that was caused by the oil filter coming off.
 
It would be interesting to see a poll on this.
Personally I always do it even though I broke out the "easy" (top) safety wire hole on the engine casting years ago, and now I always have to do it with the "impossible" (bottom) one. Just because, I'd feel pretty stupid if I didn't and the thing came loose and all the oil came out.
 
Do they safety wire a filter on the Harley Davidson? Trust me, noting vibrates and shakes more than those things. :D
 
I don't. I follow the K&N recommendation a tighten touching plus 3/4 turn.

I think 3/4 turn is way too much. I go 1/4 turn which comes to about 16-17ft/lb. And I always use safety wire. Considering the consequences, it is worth the additional 5 minutes work.
 
Here we go again.
""""Anybody got the popcorn.""""
No, I do not and have driven over a million miles (road) without a safety wire and have never had it happen or heard of anybody loosing a filter. And lightening may strike me to night, But, I use automotive filters on my I0360 too. They have a higher burst pressure than the "aircraft" filters.
If I ever sell my airplane I will put an aircraft filter on it and safety wire for looks.
That said, it really only takes a few minutes to do.
And with an automotive filter it is even faster, using the hose clamp method.
Unless some guy named "Willy" I know didn't even tighten it in the first place.
Your luck may vary Art
 
Oil filter burst pressure

If you worry about an oil filter bursting you have other major problems going on with the engine
 
At least not until there's a shortage of safety wire. :D

16-18 ft/lbs is the correct #.
I safety customers filters so they don't freak out, but not my own. :eek:
I suspect some folks may not want to publicize their use of 'non-standard' practices, however the latest "trend" of using 'non-approved' cleanable filters makes it irrelevant, I guess?
 
If you decide not to safety your filter, after it's properly installed, then place a piece if tape on the filter that you can see and confirm (when you check your oil level) that it has not moved.
 
Background on the tightening of filters.

All engine oil filters are tested under an ISO or an SAE test procedure for many qualifications. One is loosening. The 3/4 turn from first contact is part of the test procedure. This portion of the test is run with high pulsating inlet conditions and at 1/4, 2/4, and 3/4 turns of preload. Torque was never used, just mark the housing and turn. These tests once were run in our lab for branded filter product quality control. I asked the test engineers about safety wire and he laughed - - he said that 99% of the tests passed the loosening test at 1/4 turn and all passed above that.

Aviation likes to use safety wire and once it was seen on connecting rod cap bolts. Later, I worked at Contentintal and asked the engineers there. They said . ."it's aviation" and never had actually tested any filters. You might have think the aviation engineers tested way more than tractor/truck/generator engines but massively the opposite. I concluded that testing aviation would involve FAA, lawyers and questions of why now. So I don't expect a change . . . ever.

Walt is perfectly safe.

Oh - I can not find that the metal filter housings have been subjected to the standard filter test protocol in any way except maybe efficiency. Note that the regular filter does not bottom out metal to metal, but the reusable filter housing does. Extending the capabilities/tolerance of one design to another is not valid IMO.
 
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All engine oil filters are tested under an ISO or an SAE test procedure for many qualifications. One is loosening. The 3/4 turn from first contact is part of the test procedure. This portion of the test is run with high pulsating inlet conditions and at 1/4, 2/4, and 3/4 turns of preload. Torque was never used, just mark the housing and turn. These tests once were run in our lab for branded filter product quality control. I asked the test engineers about safety wire and he laughed - - he said that 99% of the tests passed the loosening test at 1/4 turn and all passed above that.

Aviation likes to use safety wire and once it was seen on connecting rod cap bolts. Later, I worked at Contentintal and asked the engineers there. They said . ."it's aviation" and never had actually tested any filters. You might have think the aviation engineers tested way more than tractor/truck/generator engines but massively the opposite. I concluded that testing aviation would involve FAA, lawyers and questions of why now. So I don't expect a change . . . ever.

Walt is perfectly safe.

Oh - I can not find that the metal filter housings have been subjected to the standard filter test protocol in any way except maybe efficiency. Note that the regular filter does not bottom out metal to metal, but the reusable filter housing does. Extending the capabilities/tolerance of one design to another is not valid IMO.

Regular filter O rings extend beyond the case by .085 and allow a crush to .040 with a 3/4 turn or torqueing to 18 ft.#.

The K&P O ring extends .025 beyond the case. Do not expect to turn it 3/4 past contact.... it won't go. Instead, torque it to 18 to 20 ft. lbs as instructed.
 
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Robinson Helicopter's Deletion of Safety Wire on Oil Filters

The Robinson Helicopter Company deleted the requirement for safety wire on oil filters on Lycoming engines (and on some other components) installed on their certified helicopters many years ago.

Below is a Service Letter from July 2013 that covers all their helicopter models.



Here is a snippet from the bottom of page 2:

i-qFBNP2r-L.jpg

Here is a link to the R-22 Handling & Maintenance Section of the POH:



Here is a snippet from page 8-9. Note the comment that safety wire is not required on the filter.

i-CXDbrr5-S.jpg


There you go! If they don’t vibrate loose on helos, they certainly won’t vibrate loose on our airplanes. (But I still use safety wire on the oil filter ... so far!) ;)
 
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Safety wiring an oil filter weighs and costs basically nothing. Takes 5 minutes, gives you the chance to practice safety wiring, avoids discussions with other folks and let you sleep better.

For that reasons some smart engineers put these holes in case and filters.

we could go further and discuss the need to safety wire the sump's plug for the oil screen etc.
 
Safety wiring an oil filter weighs and costs basically nothing. Takes 5 minutes, gives you the chance to practice safety wiring, avoids discussions with other folks and let you sleep better.

For that reasons some smart engineers put these holes in case and filters.

we could go further and discuss the need to safety wire the sump's plug for the oil screen etc.

WAIT!! Need more popcorn.
 
Sump screen

I would gladly put a whole spool of safety wire on the filter if I didn’t have to do the sump screen. I have to remove stuff to get to that and even then it is a pain in the butt!
 
I always safety. Soon will be switching to the reusable K&P filter and will safety it as well.
 
the deal is..... if u go to the extent of wiring it... then you have passed the step of tightening it... therefore you have double checked ur work.
 
I use the hoseclamp method to secure my $3.25 automotive filter. Since the hose clamp stays in place, I have not had to twist any new wire in years.

I was a jet troop in the USAF... I've twisted enough wire to last several lifetimes
 
I use the hoseclamp method to secure my $3.25 automotive filter. Since the hose clamp stays in place, I have not had to twist any new wire in years.

I was a jet troop in the USAF... I've twisted enough wire to last several lifetimes

You use the Napa Gold 2515?
 
I use the hoseclamp method to secure my $3.25 automotive filter. Since the hose clamp stays in place, I have not had to twist any new wire in years.

I was a jet troop in the USAF... I've twisted enough wire to last several lifetimes

I dont know the hose clam method. I have a 90 degree adapter so my oil filter hangs straight down and about impossible to wire. Can you explain how to do it or post a picture? Thanks
 
I dont know the hose clam method. I have a 90 degree adapter so my oil filter hangs straight down and about impossible to wire. Can you explain how to do it or post a picture? Thanks

This is putting a large hose clamp around the filter and safety wiring around the screw head to a "fixed" point.

The neat part is that you never have to cut the wire. Just loosen the clamp and slide the wire off.
 
safety wire

Ditto on the oil screen! And the cool Safety tool - very nice, just out of my price range :) ... Now back to the popcorn!
 
It would be interesting to see a poll on this.
Personally I always do it even though I broke out the "easy" (top) safety wire hole on the engine casting years ago, and now I always have to do it with the "impossible" (bottom) one. Just because, I'd feel pretty stupid if I didn't and the thing came loose and all the oil came out.

Loop the safety wire around the base of the oil temp port and twist from there. Much easier than the bottom safety wire hole in the filter adapter.
Good Luck,
Mahlon
 
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