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IO-360 oil pressure relief valve

M

Maverick972

Well Known Member
Today on my annual my A&P noticed that my oil pressure relief valve was not safety wired to the case body not the adjustment. Ok not problem, wire it up.

Then is noticed that the adjustment stem / nut what ever / was very loose and easy turns with just you fingers...he then told me it should not been this loose and it needs to be replaced.

I have not had any oil pressure readings out of ordinary and ranges are consistent.

How loose or tight should the adjustment part of the value be?

I want to investigate further before I drop 200+ on a new valve. Thanks :confused:
 
Not experienced as both my engines had non-adjustable caps, though I can't imagine that it is ok that it can be turned with light finger pressure. However, if it were me, I would examine the male and female threads. If both were in good shape, I would put a nut or jam nut on the stem and use that to hold the threaded rod in it's desired position before spending $200.

Larry
 
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Lycoming manuals available on line for free if you want to download a copy, nice to have in any case.
 
Maverick972 said:
Today on my annual my A&P noticed that my oil pressure relief valve was not safety wired to the case body not the adjustment. Ok not problem, wire it up.

Then is noticed that the adjustment stem / nut what ever / was very loose and easy turns with just you fingers...he then told me it should not been this loose and it needs to be replaced.

I have not had any oil pressure readings out of ordinary and ranges are consistent.

How loose or tight should the adjustment part of the value be?

I want to investigate further before I drop 200+ on a new valve. Thanks :confused:
Click to expand...

Something is wrong. I just replaced my leaky one with a new one and you have to use a wrench to adjust the screw.
 
Maverick972 said:
Today on my annual my A&P noticed that my oil pressure relief valve was not safety wired to the case body not the adjustment. Ok not problem, wire it up.

Then is noticed that the adjustment stem / nut what ever / was very loose and easy turns with just you fingers...he then told me it should not been this loose and it needs to be replaced.
Click to expand...

The way those things are made, I can't imagine any force which would wear the threads. In addition, spring pressure should generate some resistance to turning the adjustment screw. Guessing from afar, I suspect the adjustment screw is backed out so it is not in contact with the spring.

Simple assembly, not rocket science at all. Just screw the whole housing out of the case and inspect the parts. Reinstall at 300 in-lbs.

Oil%20Pressure%20Relief%20Valve.jpg


Oil%20Pressure%20Relief%20Components.jpg
 
DanH said:
The way those things are made, I can't imagine any force which would wear the threads. In addition, spring pressure should generate some resistance to turning the adjustment screw. Guessing from afar, I suspect the adjustment screw is backed out so it is not in contact with the spring.

Simple assembly, not rocket science at all. Just screw the whole housing out of the case and inspect the parts. Reinstall at 300 in-lbs.

Oil%20Pressure%20Relief%20Valve.jpg


Oil%20Pressure%20Relief%20Components.jpg
Click to expand...


You are correct, the screw is backed out fairly far. I think I will remove, clean and inspect.
 
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