When I was doing the 200TDi conversion, I looked at the separate oil cooler I'd bought on ebay (I decided against using the 200TDI combined radiator), and thought "those pipe stubs look a bit small!", but decided it would probably be ok.
All was well on the local trips around town, to the MOT station and back etc. but on the 'long' trip, once everything got nice and warm, and the oil pressure was well up at 60mph, one of the hoses blew off the stub and dumped the fresh oil (only changed the day before
) onto the road and all over the engine bay 
Unluckily, it happened just after an exit on the A1, and the hard shoulder was narrow with no grass to the left to pull on to, so Patrick gave me a push from behind to get to a safer place. Luckily, Patrick's Carawagon has a big towing eye on the front bumper, which he used to push my towing plate. Once we were in a better place, Patrick managed to get in front and we used our solid bar to tow me the final 8 miles or so to the campsite as I knew we didn't have enough oil to refill it even if I repaired the hose at the roadside.
This is the second time I've seen this happen - the first was John Horne's (Overlander's) 200TDi Carawagon when we were leaving Zagora to enter the Sahara in Morocco - I think we'll call it the Zagora Horne syndrome
As in that case, it was just a matter of reconnecting the hose, with a new Jubilee clamp, and scrabbling round for another 6.5l of engine oil.
It was fine after that, but I kept the revs low so the pressure wasn't too high, changing up early and sticking to 45-50mph in overdrive on the journey back.
Anyway, I'm on the lookout now for an oil cooler with a bigger bore and hopefully, threaded unions, oh, and a load of engine cleaner to clean the engine bay
Cheers,
Robin.
).