On Fri, 14 Apr 2017 14:05:19 -0400, Frank "frank wrote:

On 4/14/2017 1:57 PM, (PeteCresswell) wrote:
Per Frank:
I made mistake of greasing an o-ring on my water filter housing with
Vaseline and it expanded too much. I easily shrunk it back with careful
heating with a heat gun.

I tried that once, but no-go.

Sounds like I am going to try it again - with a little more heat and
time.

Worth trying. Worse you could do was have to buy a new gasket. The
o-ring for my unit listed for $11 which I think is outlandish. OEM
suppliers can hose you with parts cost.
Try shrinking it with alcohol. It extracts the petroleum from the
ring, shrinking it.

If it wa ME I'd try to get an industrial o-ring that is resistant to
petroleum products - and likely het it for about 1/4 the cost of the
OEM part.