S1 Heater control Valve

Recently I changed the rubber o-ring in the valve (yes, the proper one) . Finally got around to running the car till hot then checking------STILL leaking from what appears to be the valve itself. Can these be taken apart and repaired? I ordered an aftermarket one which was basically crap, so returned it.

I think they are the same for an S1 or S2 (C17820)… the one I recently got from Terry’s works fine though I did reuse the old seal rather than risk a new one.

By proper one do you mean one with a triangular profile? I had no luck with the fat O-ring usually supplied.

Here is the one I refer to:

But when I ordered I got a plain O-ring (on right) which did not successfully seal:

Yes, you can take the valve apart to inspect/repair them. I had to do this to one of my E-types when the valve started leaking, and the new one that I bought was cracked/junk. I was able to use part of the old valve, and the head/innerds from the new junk valve. You drill the pop rivet and take it out, then the top rotates to align the crimps with the slots in the body of the valve, and it comes apart.

actually, I don’t remember if it was like the one on the left or not. What I do know is that the original was badly worn and crumbled as i removed it. when it leaks as a result of the seal, where does it drip from?

On mine it leaked into the driver’s footwell (and gave me a few bad moments as I had just replaced all the pipes).