O Rings for 01m valve body harness port

My experience or acquired knowledge on these parts has thought me that , in this case there are standard sizes of o rings made by companies who do just that and they supply people like vw and whichever company. So VW does not make the ring. What needs to be identified is not necessarily the oring that comes with the harness but rather what the size the O- ring is and most importantly what is the best material that an O ring is made of to suit the requirement. So if your OR has failed it will have to be replaced and to replace it , it has to be removed . With that in hand you have the size but I would not replace it with that type of ring. I just went through this and thats why im here.
I have looked and everything (almost) that people or suggesting is what ive read here , basically go with the same one. My feeling on that is " why would you"? They fail ! and most are made of some Nitrile. Here in Philadelphia there are extremely cold nights and I think that that's where the Nitrile is not suited. My car was sitting in my unheated garage where I've been working on it for about 3 months . Today i started the engine just to move the car around in the garage, I didn't go anywhere. I ran it for 1 or 2 minutes , turned it off and I looked on the ground and there was trans fluid on the ground and a decent amount of it too.. I looked up to the port where the harness enters because it was where it was wettest. I removed the the harness to get the ring and I put it next to a new ring and you could see that outer edge had lost its well defined roundness. It was more like a flattened outer edge. Whatever rings are being put on these harnesses , i really dont thing that proper thought is being put into the choosing of the correct material and the very important roll that this seemingly insignificant little piece of rubber plays. So to find a ring that has a firmness butyet slightly spongy and does not loose that quality when the winter temps are down in the teens when there are temps of 200 c up , maybe to 300 -400 c
. Then of course there's the chemical reaction of the ATF with whatever ring material is chosen. Yes this could drive a person insane, finding the perfect ring. But the ones that I've experienced that came standard , have all failed miserably. The ring that just failed on me was only , not even 2 years and maybe 2000 miles max. This is not acceptable and my lesson from this is stop depending on what the manufacturers are suggesting to use. Do your own homework . I have the ring in my pocket and tomorrow I'm going to an engineering company to quiz them and I'm leaning toward Butyl as my next ring to experiment with . Anyway don't depend on asking anyone or most at the dealership, they really do not know. They cant say that they dont know so they'll say something but it wont be based upon their years of education on seals and gaskets . I need facts backed up by being proven over time and extreme temps in a real situation. Trial and error and scientific factual data.
Damn , that was a long rant.
So has anyone out there found the perfect Oring especially for the valve body harness port on the 01m. , WHAT IS IT MADE OF ? That's mainly all I need to know. Now of course if you have a code or a specific site where I can get it rather than going through a hundred hardware stores , that'd be great.
Thanks for any info ahead of time . GO EAGLES!

Check with CoolAirVW (or via KansasCityTDI.com).

Generally it's only a matter of temperature and fluid ratings. McMaster-Carr has just about anything one would want for things like this.

ODONOVJ said:

Here in Philadelphia there are extremely cold nights and I think that that's where the Nitrile is not suited.

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I dont think the cold is the issue, otherwise there would be a million posts from all the northern states and Canada, and Northern Europe (tons of Vw's, but not many with auto trans though) for that reason saying "my harness o-ring is leaking".

ODONOVJ said:

My car was sitting in my unheated garage where I've been working on it for about 3 months .

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A car that sits for long periods of time might tend to leak there more as the fluid in the converter will drain back into pan and fluid level in the pan becomes higher submerging that area. This is where I would focus my energy if I were you.

ODONOVJ said:

I removed the the harness to get the ring and I put it next to a new ring and you could see that outer edge had lost its well defined roundness. It was more like a flattened outer edge.

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That's what old rings look like that have worn and shrank over time. That's weird. If it was replaced then it should still have a "round cross section" and not be flat. With this one point makes me wonder if your right and the material is poor.

ODONOVJ said:

Whatever rings are being put on these harnesses, i really dont thing that proper thought is being put into the choosing of the correct material and the very important roll that this seemingly insignificant little piece of rubber plays.

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I'm not so sure, because if that was the case there would be a million people in cold areas with the same problem you have. I hear about this stuff, and "follow" it and there are hardly ever complaints of leak there, but when there is a new ring or harness usually solves it.

I read an article in transmission trade magazine (transmission digest or gears magazine)years ago about o-ring materials. I remember some of the info, but I remember nothing mentioned its ability to "live" in cold weather. Which makes me think OP is asking the wrong question. Compatibility was discussed but only mentioned "incompatibility" with things like mineral spirits. (for instance don't clean silicone o-rings in mineral spirits or they swell to unuseable size). All the materials that I remember would be fine for ATF. I remember abrasion being discussed, as silicone is more prone to cutting during installation.

The article mentioned how to identify the material which seems to be one major thrust of OPONOVJ's question, and the way is to burn it. The color of the flame helps identify the material. Its possible you could find this article by going the the websites of the above mentioned magazines to see if they have an archive. They sometimes sell old issues also.

I googled "transmission digest o-ring material" and got nothing quickly about the article but lots of stuff about o-ring material. You should look through that stuff.

ODONOVJ said:

WHAT IS IT MADE OF? That's mainly all I need to know.

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Maybe google will give you info on it, and you can burn it and see.

ODONOVJ said:

Now of course if you have a code or a specific site where I can get it rather than going through a hundred hardware stores , that'd be great.

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Some folks on here have used "the o-ring store" for various things. I've browsed their site and they do have info on different materials, be sure and share what you learn here. They sell different materials also, and list their o-rings by size.

Oh, and one last note: Obviously your o-ring is flat, but maybe you should just replace it and then make sure your car is started once every two weeks or so, so that the converter drainback is minimized and then it might never leak????

Oh, on a humerous side note, I'm suprised the 01m haters haven't jumped into this thread and said, "The only way to fix a leaking o-ring on a 01m is to convert to 5 speed!".

LOL, that o-ring is at least as good as the transmission it is used on. WAY overthinking this. Just replace it with a new one, count your blessings the transmission still works at all, and move on.

oilhammer said:

LOL, that o-ring is at least as good as the transmission it is used on. WAY overthinking this. Just replace it with a new one, count your blessings the transmission still works at all, and move on.

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That's kind of what I thought too, but taking into account driainback, if the car was started regularly it might not leak at all.

Get off this forum! You dont even own a tdi anymore! Go get on your BMW diesel forums ya traitor!

(please dont ban me as Dogdots is a freind, partner ect, and its just in good fun!)

Apple Rubber is a good source for o-rings. Very popular in the high tech field. They make custom sizes too. As an added benefit, when a company orders a custom size, that size is then offered to the public. Very useful is some instances.

http://www.applerubber.com/