All knowing beeb: Identify this oil drain plug!

So I'm changing the oil on an RV onboard generator (Onan QD3200) and I come across the oil drain plug. Normally I always replace these with magnetic plugs, but as I'm servicing it I come across this:



In all my years I've never seen a two-piece oil drain plug like this; it's a cap that unscrews, and the center is a separate piece that drops out and apparently maintains it's seal to the outer cap using an o-ring inside the cap.

Can anybody tell me what standard this is / who makes it / is it common? Been looking all over and I can't find any info. I understand it's an extension piece for the original drain, but I'd still like to get a replacement magnetic cap for it if possible.

Thanks in advance for any help.

 

its an AN fitting. used on aircraft. depending on the size, I might have some laying around that I robbed from an A-4 Skyhawk.

cars use them too, for fuel line and oil lines.

 

Boom! 7 mins for the answer!

 

Yup - Dave knows his stuff for sure :up:

Now then...why - WHY - would they use this for a drain plug? There's no pressurized line, no level of aircraft safety required...ugh.

Just seems way complicated for 'unscrew and watch fluid come out'. And I still can't find a magnetized fitting for it

 

I would guess that it's to allow the oil to be drained into a container without making a howling mess.

That would require a hose, however.

Does the elbow swivel?

 

yep. its so you can put a hose on it to remotely drain it. I'm sure the generator is used in multiple applications and positions. measure the I.D. of the 90* fitting, or if there might be a number stamped on the cap. I will check my "box 'o junk" tomorrow.

 

They do it because of the hole they put there for the drain... The fitting would allow the oil to drain out of the hole vs on the panel, then run out of the hole. Just a different way to do it. They make those caps in single piece as well, if the two piece cap drives you nuts.

This should be the size you have... http://www.summitracing.com/parts/aer-fbm3602/overview/

 

Yep, standard AN stuff. Like someone else said, if you want to replace it measure the ID and round to the nearest 1/16. Then whatever number is in the top of the fraction is your AN fitting size. I doubt they make them in magnetic versions though, and actually in this application I doubt it would do much good since once the oil is filled, the oil leading up to the drain plug is probably stagnant.

 

Aircraft 'quick drain' plug would be the upgrade

 

What he said. :up::up:

You will sell or trade that in before it even needs another oil change anyway.

 

Love that thing on my RV4. Easy to get hose fitted to that nozzle too. Doesn't do me any good as I can't reach it without removing the cowl anyway but cool feature for those that could.

 

Nice. I'm going to see about losing that elbow altogether and installing one of these :up:

Haters gonna hate.

 

If you take the elbow out and install one of those plugs you won't actually be draining all of the oil out unless the generator is tilted toward the plug. If that plug is installed horizontally, oil will remain in the sump up to the edge of the blue center part. I believe those are intended to be installed vertically.