Quote Originally Posted by Bitsyncmaster View Post
It only takes about a one or two hour soak in gasohol if you have some calipers to do the test I did.

Measure each before you soak, Tag which is which, soak and remeasure. I would like another verify of what you find.

The problem is we really do not know exactly what the originals were made of. What they sell today and call Buna N is probably not what they used to make. Whatever the originals were made of, it seemed to be OK. The problems seem to start once you change them. There are plenty of mixture units out there with the original "O" rings in them and they function just fine. If you should replace them I would suggest you try to use Viton of the correct size since what they pass off as Buna N is not going to work. I believe one of the problems is that the Buna N swells and since this is a dynamic seal (the "O" rings are on parts that move) when it swells it gets chopped as it moves over the slots. If it was just used to seal a part that doesn't move (like a drain plug) where it is captured and cannot swell, Buna N seems to be fine.