Oil filter torquing vs hand tight plus 3/4 turn

[helitim]

It is my understanding there are basically two distinctively different methods of tightening an oil filter. Hand tight plus a 3/4 turn and, torque to 18 lb ft. On my last 50 hour I couldn't conveniently find my torque wrench so I did the hand tight plus method. The first 10 hours was uneventful then, I had an unexpected oil leak suddenly manifest. 1.5 qt per hour. Upon inspection, I found the oil filter surprisingly loose even though it was safety wired as has always been done. Replaced the filter and torqued to value. Safety wire added and leak is stopped.

It's pretty obvious that something I did was incorrect in tightening the filter. It's such a simple task, I just can't imagine what I did wrong. An additional concern is why would it take 10 hrs for a leak to manifest? From now on, it will be nothing but torque tightening after this incident for me

Tim

[Hank]

Make sure you connect the safety wire so that rotation to unscrew is held to the absolute minimum. Moving 1/4" or so would loosen it enough to leak.

[helitim]

The safety wire was on correctly. I'm posting this to get input and to hopefully remind others to just be careful when performing tasks that may seem mundane and repetitious. I would have never believed I could let something this simple happen to my plane. Always be vigilant when working on aircraft. No one is immune to mistakes.

[helitim]

Hank,

If you're ever flying up just NE of Birmingham and happen to fly over WILED intersection, look down and you will see the grass strip and home I built there a few years ago.

Tim

[Hank]

Thanks, Tim. I'll keep a look out. Yell if you're down this way.

You coming down for Summit? I'll be there, even if I have to drive.

[mike_elliott]

The safety wire was on correctly. I'm posting this to get input and to hopefully remind others to just be careful when performing tasks that may seem mundane and repetitious. I would have never believed I could let something this simple happen to my plane. Always be vigilant when working on aircraft. No one is immune to mistakes.

Great reminder. While not an A$P, I have done a bit of work under supervision and follow every task with this question "what is the worst thing that could happen here". I also NEVER put a nut on a bolt without torqueing it properly. No just putting it on to hold it in place, to keep track of it, etc...Way to easy to overlook its proper installation that way. Double check everything when you have your wrenches out. 

[M20F]

The safety wire was on correctly

If it was on correctly then the filter wouldn't have backed off the fitting.

[cliffy]

3 things to bear in mind on oil filters-

Use DC4 compound on the rubber seal not oil or grease.

Use 18 ft lbs of torque with a torque wrench

Make sure the safety wire is tight and correctly wound UNLIKE Robinson helicopters that just dropped safety wiring oil filters

on their helicopters. In fact the new oil filters for Robinson come with their name on them AND NO SAFETY WIRE CAPABILITY 

[jetdriven]

That's odd, I have done the 18-21 FTLB torque and now I just go gasket contact plus 3/4 turn. It actually works out to 20 FTLB. I do mark the filter before turning it the 3/4 turn so I get it precise.

Vans RV guys use Napa or Wix oil filters and put a large hose clamp on the filter case and safety that.

[RLCarter]

Hand tight + 3/4 turn will result in a different torque almost every time, your ability to get a grip on the filter might greater or less than the guy standing beside you. The oil filter torque wrench for me is a gadget and just another thing that needs calibrated, I use the stamped steel wrench one which is actually a torque wrench adapter, if you don't feel like doing the math each time just stamp or engrave it on the wrench.

[jetdriven]

What do you do on a plane that you can't fit a torque wrench on? The hand tight + 3/4 turn method is legal, it's stamped on the side of it.

[N601RX]

It's all about compression of the gasket the correct amount. I would think that hand tight+3/4 would give a more consistent compression provided the hand tight point is correctly identified. Torque measurements is very subjective to friction. Most of the torque goes into overcoming the friction (hence DC4). Critical bolts are usually measured by stretch.

[DXB]

Is there too much subjectivity to the "hand tight?"   What feels hand tight in the awkward confines at the back of my engine compartment could be quite different in a wide open space in another model.  I struggle to get it threaded past the loose "easy" part back there by hand before I put the torque wrench on it.   My hand cramps up from the awkward position - this could deceive me into thinking it was tight when it's not. 

[Bob_Belville]

I have 2 sizes torque wrenches in the hanger. Spark plugs, oil filters, and Concorde batteries cable connections all have torque specs. 

[Shadrach]

Hand tight + 3/4 turn will result in a different torque almost every time, your ability to get a grip on the filter might greater or less than the guy standing beside you. The oil filter torque wrench for me is a gadget and just another thing that needs calibrated, I use the stamped steel wrench one which is actually a torque wrench adapter, if you don't feel like doing the math each time just stamp or engrave it on the wrench.

 

 

If I am doing it, I think it's pretty consistent.  I have never had a leak, and I've never had any trouble at removal.  I think the problem is the "hand tight" part...that can mean many things to many people.  What it should be is "well seated" + 3/4 turn.  I believe the OP simply needs someone to show him how it should look and feel.  I find a torque wrench to be more trouble than it's worth for an oil filter.   

[FoxMike]

My experience with oil filters for the past 40 yrs or so is the hand tighten+ 3/4 works ok.  Since I have to have my torque wrench calibrated every year I currently use the 18ft/lb.  I have had two filters leak over all these years, one probably was result of not enough torque and the other a slightly deformed filter case.  A slight leak makes a mess giving notice to troubleshoot, a big leak can be catastrophic.

[Raptor05121]

What do you do on a plane that you can't fit a torque wrench on? The hand tight + 3/4 turn method is legal, it's stamped on the side of it.

This. 18ft-lbs is 18ft-lbs, regardless if you used a torque wrench or a mathematical formula for brute strength and measured turns.

[RLCarter]

'Hand Tight" is the issue, it should be until the sealing gasket contacts the sealing surface, then the 3/4 turn. We can split hairs, but either method (hand or torque wrench) works as long as the method is done correctly. Temperature, friction of the threads and seal....etc ALL will alter the "Actual" torque. Why did Tim's filter come loose? Who knows, seal shrinkage, safety wire too loose, burr on the threads giving a false feeling of being seated or a combination of things. Not having an answer as to why, I would put some marks on it and check it often for movement

[Yetti]

This. 18ft-lbs is 18ft-lbs, regardless if you used a torque wrench or a mathematical formula for brute strength and measured turns.

Is that wet or dry 18 ft lbs?   I recall the BMW motorcycle board got into a multi page discussion about weather the bolts should be cleaned or not before torquing

[jetdriven]

Generally torque assumes oily threads. Not used by the installer, but residual oil left over from the manufacturing process. Brake cleaner for example will make the bolt torque much earlier than design clamp load. An oil filter isn't torquing the threads, really. It's compressing the gasket

[Guest]

This. 18ft-lbs is 18ft-lbs, regardless if you used a torque wrench or a mathematical formula for brute strength and measured turns.

Not necessarily, if you're using the Tempest filter torque wrench or a torque wrench and a socket yes, if you're using the Tempest torque wrench extension (crows foot) the torque value can be different, depending on its use method.

Clarence

[Marauder]

Not necessarily, if you're using the Tempest filter torque wrench or a torque wrench and a socket yes, if you're using the Tempest torque wrench extension (crows foot) the torque value can be different, depending on its use method.

Clarence

Found that out firsthand over tightening wheel lugs on my Jeep. Magilla Gorilla...

Sent from my iPad using Tapatalk

[jetdriven]

I'm not sure what you're showing there

[Guest]

One of his broken nuts!

Clarence

[Bob_Belville]

The Marauder is either bragging or confessing operator error using a device far too complex.