Thread: o ring size - help

Are you referring to the heater core O rings? I would only get the correct ones as the labour involved is not worth making a mistake

Heater matrix o ring x2 range rover p38 | eBay

What wayneg said x 2, only get the proper o rings.
When you tighten the screw, be careful not to overtighten, as you can cause cracks in the surrounding plastic.
You can check it before you reassemble everything, refill the coolant and run it up to temp to check for any leaks.
When I did mine, first go was too loose and still had the leak, tightened a bit more and the leak was gone.

No. Its not heater matrix o rings. Its the pipe leaving the inlet manifold - it feeds coolant from the manifold to the matrix. It is located immediately behind the alternator.
Ive just pulled the engine out and done lots of work on it. I put it back in yesterday and It all fired up with god oil pressure etc but I have this rotten leak at this pipe outlet. I measured the original oring with digital calipers and matched it to an imperial size o ring from my o ring kits - but no luck.

Hi

Is it one of the ones in this diagram?

Allbrit.de - Ersatzteile für LAND ROVER & MG ROVER

Steve

Yes it is number 8 on that diagram.
The correct part number is ERR6434.

I received two genuine O rings today and I can reveal the following.
1. The correct size is 19mm ID and cross section 2.5mm.
2. Material for high temp coolant applications is NBR - Nitrile rubber.
3. Correct caterpiller part number is 217-3875 if you want to buy it at other than Landrover.

The problem was that when I took the part out on Saturday afternoon,I didn't know that the existing o ring had a swollen cross section- so measuring it with digital calipers gave the wrong size as a SAE size 116 which is 18.72mm by 2.62mm. This SAE size gave a significant leak.

Thanks anyway to all.