[Jeeper6]

Good find drover...as genpk wrote too, wonder how good they are? I have a cooler I bought of ebay a fair while ago that I carried on my lap "just in case".

I am going to have the cooler replaced around 150k as insurance anyway. But I guess it would be very possible to buy a dud to replace what has not yet failed.
That would give you the irits!

It would be interesting too to know whether it is actually gasket / seal failure a lot of the time, or does the internal honeycomb setup fail. When I had the cooler go in my last Jeep, I got the cooler and mounting bracket assembly back from the workshop to check it over. I didn't find it practical to attempt pulling the cooler itself apart looking for a failure point, as it would only need to be a very slight crack to allow oil to escape under pressure...you'd do more damage just pulling it apart.