JX Oil cooler seal

[JonB]

I've got a new JP Oil Cooler and rubber O-ring. Having fitted, torqued to 25Nm put a new oil filter on and filled up with oil when I ran the engine I had quite a significant oil leak from the cooler/O-ring.

I've stripped it down but before I go for another attempt any ideas why it might be leaking? I didn't use any sealant on the cooler surface or the ring as per Bentley, I do have some Dirko though. If I do apply some dirko how thick does it need to be?

One other thing I'm wondering if the thickness of the oil cooler could be different or that the filter union tube might not be full screwed doesn't move by hand, is that a 2 nut job to tighten?

[Aidan]

what brand O ring seal ?
Personally I would only use genuine, or Febi if that's all I could find, rather than a JP one
Genuine available on Amazon, maybe elsewhere, yes they are many times the price of a JP or a Febi one, the genuine ones were £7 from VW 15 years ago, it has a hard life. Check the block isn't pitted.

[JonB]

Thanks Aiden, the cooler came with one in the box but I also have a spare from brickworks which should be Febi. I'll use that and try to be meticulous in eyeballing everything.

[JonB]

Meh, that was annoying task last weekend. Tried a couple of times with the new JP cooler and Febi rings but all with some degree of weep. Cleaned up the old Vemo one and put on with a Febi ring and sealed no problem. Bit of expense and time that ultimately wasn't worth it.

The only thing I did differently with the old one was that I have 2 27mm nuts so I could tighten the tube up but was maybe only 3/4 of a turn. Maybe was this but maybe still the cooler?