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-   -   Oil drain (https://vansairforce.net/community/showthread.php?t=205721)

rondawes 04-19-2022 05:36 PM

Oil drain
 
1 Attachment(s)
So today, I was puttering around at the hangar with my RV-7A that I've had for less than a year. It had a condition inspection and oil change just before I bought it plus a pre-buy by a different person. Due to a number of reasons, I've only flown it 40 hours or so in the 10 months I've had it.

So today, I looked down below the exhaust and saw a small oil drip on the floor. "Hmm, this is the first drip I've seen from this plane." I got a light and looked up at the drain plug and quick drain and saw it leaking as in the attached photo. Now, I'm no A&P but that safety wire doesn't look like the ones on the how-to YouTube videos or even the few that I've done. As funky as it is, I'm glad it kept the drain plug from coming all the way out. That would have been a bad day.

rondawes 04-19-2022 05:44 PM

I did not have time today to work on it. I'm figuring that I'll have to drop the lower cowl.

Bavafa 04-19-2022 06:03 PM

This deserve an award
But seriously, no big deal just remove and put a proper safety wire.
Two other note, is the oil is coming from the drain or from your sniffle valve? If you have a sniffle valve, more likely is coming from that which is normal.
Also please note that oil change is based on run time and calendar time, 4 months intervals

Stevea 04-19-2022 06:40 PM

oil drain leaks
 
1 Attachment(s)
One of three things:

1. Leaking from above the drain valve.

or

2. Leaking out of the drain valve pipe threads. Remove, re-goop the threads with pipe thread sealant, reinstall, safety wire.

or

3. o-rings inside the drain valve are leaking.

If it is the o-rings, not a big problem. You can fix it for about $3 worth of o-rings...mil spec o-rings from Aircraft Spruce. Just make sure to get the mil-spec ones from Spruce, or some aviation supplier. DO NOT go to your local big box store and shop the plumbing isle. Yea, you may find the right size, and they may work for a while....but the material may not be suitable for an oil seal. Big box store plumbing isle o-rings belong somewhere under your sink, or in a bathroom faucet keeping the water inside your house pipes......not in the valve holding oil inside your expensive Lycoming.

Here's a photo of mine, recently overhauled after reaching 1000 hours. It did not leak, I just did it as preventive maintenance. The o-rings I took out were a bit harder than the new ones, but they still were doing the job.

The valve is easy to take apart. Remove the clip. Remove the top two o-rings. Disassemble the valve. Remove the bottom o-ring. Be careful not to scratch the o-ring seating surfaces on the aluminum parts. Use a plastic pick or o-ring tool to get them out.

One last thing: here is where to find the o-ring part number for your valve, a Saf-Air P5000 oil drain valve.
https://www.saf-air.com/products/o-rings.html

rondawes 04-19-2022 07:31 PM

Thanks for the suggestions. It's leaking from the threads where the valve goes into the case. I could reach up there and slightly rotate the valve. I'll know more when I actually look at it in detail. I had run out of time today when I found it.

Stevea 04-19-2022 11:59 PM

The blue part of the valve may move very very slightly when twisted. The silver part SHOULD NOT rotate at all when twisted. If it is only installed finger tight, stop, do not pass go, do not fly the airplane, until the valve is properly torqued. Maybe youíll get lucky and only need to tighten the valve in another turn or so. Most definitely worth pulling the cowl and getting to the bottom of things.

Oh, and re-do the safety wire at least. Single wire is not the preferred method, but is ok to use. But, the twist connection on that one is kind of ugly, and maybe not acceptable. :) (not sure without looking it up)

rongawer 04-20-2022 09:51 AM

Stahlbus
 
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I recommend the Stahlbus quick drain. It has a quick 1/4 turn insert, which is easier IMO than the "shove a hose on and then push and turn" method. But the real benefit is a cap with an o-ring to know for certain the drain isn't leaking.

Perfect fit for a Lycoming oil pan: Stahlbus NPT 1/2-14 oil drain

Here's the only photo I could find that I have on hand:

BobTurner 04-20-2022 07:41 PM

Itís hard to tell in this photo, but is it possible the safety wire was originally backwards? We once had an O470 come out of a reasonably well respected engine shop with every single oil pan bolt on one side safety wired backwards. It happens.

rv8ch 04-21-2022 04:27 AM

Quote:

Originally Posted by rongawer (Post 1603588)
I recommend the Stahlbus quick drain. It has a quick 1/4 turn insert, which is easier IMO than the "shove a hose on and then push and turn" method. But the real benefit is a cap with an o-ring to know for certain the drain isn't leaking.

Perfect fit for a Lycoming oil pan: Stahlbus 1/2" NPT drain

Here's the only photo I could find that I have on hand:

Ron, this looks like a very good drain valve. I can't find a 1/2" NPT though - they seem to only have UNF, which seems to be different. Is this a typo? Thanks!

rondawes 04-21-2022 10:48 AM

Quote:

Originally Posted by rv8ch (Post 1603799)
Ron, this looks like a very good drain valve. I can't find a 1/2" NPT though - they seem to only have UNF, which seems to be different. Is this a typo? Thanks!

Interesting. I looked on the stahlbus-us.com website and they don't seem to have a 1/2" NPT version there either. I sent them an email inquiring about it. The phone number goes to voice mail.


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