Oil Fill O Ring Substitute?

[kayseventyfive]

My oil fill plug is weeping a little oil, which attracts dust. Is there an inch measurement O ring that is a good substitute? I like to use Viton O rings for problem areas, but the size (25 X 2.7) does not seem to convert well.

Or should I consider removing a little material from the sealing surface of the cap to compress the OEM seal a little more?

 

[98lee]

My oil fill plug is weeping a little oil, which attracts dust. Is there an inch measurement O ring that is a good substitute? I like to use Viton O rings for problem areas, but the size (25 X 2.7) does not seem to convert well.

Or should I consider removing a little material from the sealing surface of the cap to compress the OEM seal a little more?

I use SAE size O-rings with no problems. I'll get back to you tomorrow morning with the size. I'm assuming we are talking about a K75 here.

 

[98lee]

I use a 1"I.D. x 1 1/4" O.D. x 1/8"W Nominal size.

The actual size is .984" (25mm) I.D. x .139"W. This is .033" THICKER than the stock 2.7mm (.106") so you don't have the "bottoming out" problem you are having now. Works great.


The Parker Seals part# is 2-214 available in Viton or Buna-N.

The Anchor Packing part# is 50-214.

The AN# (if you're around aircraft or the military) is AN 6227-19. Not sure if there is a separate # for Viton but, I would imagine there is. I really don't think Viton is needed. The extra thickness definitely helps though.

 

[kayseventyfive]

I use a 1"I.D. x 1 1/4" O.D. x 1/8"W Nominal size.

The actual size is .984" (25mm) I.D. x .139"W. This is .033" THICKER than the stock 2.7mm (.106") so you don't have the "bottoming out" problem you are having now. Works great.


The Parker Seals part# is 2-214 available in Viton or Buna-N.

The Anchor Packing part# is 50-214.

Thank you so much, Lee. That size information helps a lot. Now I can do it all without interruption and with only one trip to the store.

The AN# (if you're around aircraft or the military) is AN 6227-19. Not sure if there is a separate # for Viton but, I would imagine there is. I really don't think Viton is needed. The extra thickness definitely helps though.

The AN6227-19 converts to MS28775-214, which is listed for 5606 petroleum-based hydraulic fluid, a fairly benign substance. No reference is made to either fuel or lubricant, however, in our application, that probably is not an issue, since the seal is not in constant direct contact.

The Viton number is MS9388-214 or M83248/1-214 . It is likely that the Viton is overkill, but it is listed as being suitable for synthetic lubricants and has excellent resistance to compression set. The excellent resistance to compression set is what makes me lean toward it. It also has superior heat resistance, going up to 400 deg F, but that is not an issue here. Coming from a Corvair and (early) Chrysler Hemi (and Slant Six) background, I am a little partial to Viton.

As for Buna N, it is a little hinky about esters. Some synthetic oils contain diesters, so the connection is a little tenuous, but only high-nitrile Buna N is recommended for some synthetics. Not being a petroleum engineer, I am a little over my head on some of this, but I lived through the introduction of synthetic oil on jet engines, as well as the transition from petroleum hydraulic fluid to esters(Skydrol), and we had a lot of hard lessons, which has made me a little chary.

To add to my thing with synthetic oil and seals, I recently had to replace a rear main seal on a Chevy LT1 engine because changing to Mobil 1 dissolved the adhesive holding the rubber part of the seal to the metal housing. That is a lousy job on a Jag conversion, because the engine needs two shoehorns and lots of KY to get out and back in. Ended up removing the trans, which is no fun parked on a slanted driveway. GRRR.