Cooler Oil Hose O-Ring Replacement

Rodplunger · Post by **Rodplunger** » 07 Jan 2020, 19:09

Hi All,
This might be somewhere else, but I can't find it... I am replacing a leaking O-Ring on the cooler hose at the radiator fitting. The new ring is obviously still "large" and is not going into the housing with any ease. Are there any tricks to getting the new o-ring in? Grease? I would guess the oil itself would be enough lube, but I can't for the life of me get it to slide in... I am putting an OEM o-ring in that I bought at a dealer. Thanks for any advice.

I have attached photos of the before and after. The black one was the leaking gasket. It was firm and brittle. The green one is the OEM from the dealer. It is obviously larger than the original, as it should be. The other picture shows how far I can get the green ring into the fitting...

Post by **hausmeister** » 08 Jan 2020, 02:08

You can use silicone grease/spray or just engine oil... any oil should be fine I think.
If I remember correctly they can be a bit hard to get in (what she said) try some force as long as the oring is not cut up it should be fine.

Post by **abscate** » 08 Jan 2020, 04:30

A vice grip clamped on the back of the metal pipe, behind the flange, will give you good leverage your push that in

Post by **volvolugnut** » 08 Jan 2020, 18:23

That O-ring does not have the 'look' of a typical O-ring sized for sliding fit. Perhaps the dealer supplied the O-ring for transmission cooler? Does it fit the groove width with a little gap? It kind of looks like the cross section diameter is too large for this application. That would make the outside diameter too large even if the inside diameter is correct.
When an O-ring gets compressed and flattened it has to expand in width. It does not really get compressed, it gets deformed.
I used to design O-ring sealing joints for machinery.
volvolugnut

Rodplunger · Post by **Rodplunger** » 08 Jan 2020, 18:49

I went to a different dealer, and it seems they gave me the wrong one. I picked up a black one that was much more similar to the one I pulled out of the car. I believe you are right about the green one being for the thermostat side... The new one fit very easily. Now to check for leaks.

Post by **abscate** » 08 Jan 2020, 19:48

volvolugnut wrote: 08 Jan 2020, 18:23 That O-ring does not have the 'look' of a typical O-ring sized for sliding fit. Perhaps the dealer supplied the O-ring for transmission cooler? Does it fit the groove width with a little gap? It kind of looks like the cross section diameter is too large for this application. That would make the outside diameter too large even if the inside diameter is correct.
When an O-ring gets compressed and flattened it has to expand in width. It does not really get compressed, it gets deformed.
I used to design O-ring sealing joints for machinery.
volvolugnut

This is a truly great , on point post with keen observational skills

+1000 MVS points and three passes for missing Oxford Commas, non-expiring and can be retroactively applied.

Post by **volvolugnut** » 09 Jan 2020, 16:03

abscate wrote: 08 Jan 2020, 19:48 This is a truly great , on point post with keen observational skills

+1000 MVS points and three passes for missing Oxford Commas, non-expiring and can be retroactively applied.

Thanks for the kind words. This old dog can still hunt.

volvolugnut