www.jec.org.uk

Put coolant in my car today. Fortunately no leaks so far with the exception of my new heater valve. I understand that the original seal may not be available any longer. I used a single "O" ring which I thought would do the job but it obviously has not. I did not use any type of sealant between the mounting face on the heater box and the valve. Perhaps I should have?

I would appreciate any suggestions or tips on how to deal with this issue. Thank you!

Lin

Hello Lin,

as it is a simple design, my thought is that the 'O' ring is the wrong size, either in diameter or the section of the 'O' ring is too small? Using a high temperature silicone sealant would probably do the job but I don't like that route.

Alec

Lin,
I don't recall an annulus machined into the valve face to take an O ring.

I would suggest you obtain some gasket material and jointing compound like Red Hermatite or Hylamar from say Halfords.

Remove the valve and use the valve mounting face as a template to cut out a new gasket. Draw around with a Biro and down the mounting holes and cut out using a new blade in a Stanley knife. A thin application of jointing compound to both sides of the new gasket and reassemble.

Job done

Got the proper "O" ring from Terry's Jaguar. Fit like a charm and no more leaking. I can't explain why the one I had was undersized but I am pleased that I now have the proper one in place! Thank you to respondents.
Lin

Lin,
That's interesting, is there an annulus into which the "O" ring fits ?

Hello Oldtimer,

in the distant recess of my memory. a 45 degree shamfer on the face of the valve where the O ring sits?

Alec