Hi folks, finally traced my coolant leak to the snap-connector pipes that plug into the front of the thermostat ( a and b below ). Whilst it had been pooling at the back of the valley and running off the back of the engine, I couldn't initially see any signs from the pipes until I actually saw it dripped tonight from the pipe connector.

I know there are other threads on about this, but it is possible to fit replacement o-rings into the pipes for a few quid rather than £200+ for a new pipe. I know that there are some threads on here about the tapered white coloured o-ring ... thats just a matching locator for the taper on the thermostat housing... the rubber o-ring sits in behind that.

But does anyone definitely know the size of the o-ring needed for each of them? Or if not, can anyone tell me the outer diameter of the pipes labelled a and b in the picture? I'm thinking its 40mm x 4mm ... but dont want to get the wrong size in before I pull the pipe off!


 V8 or else ...