Update on Saturdays Blog
We brought the oil cooler home with us so that I could check it out and hopeful prove it was the cause of the oil in the cooling water. A visual inspection following cleaning showed no obvious faults so a pressure test was required. After a bit of thought I decide to obtain a Schrader Valve as used in car wheels to connect to an air pump. I thought I may have to drill a suitable hole in something to install it, but in the end it turns out its an exact fit in the nut of a 15mm compression plumbing fitting, just a case of leaving the olive out.
The oil ports in the cooler already had 15mm compressions fitted so I put a blanked off piece of 15mm copper water pipe into one and the Schrader valve in the other, with this arrangement I could pressurise the oil side with a tyre compressor.Within seconds of pumping it up it was obvious there was a leak as the pressure dropped rapidly and I could hear a hiss, but it wasn't where I expected, it was where the end caps were attached to the barrel. The liquid I used to flush the cooler out could be seen blowing through. I was expecting to have to immerse the cooler in water and look for bubbles.
I was very pleased to find this as it proves this is where the fault was and replacing the cooler is relatively cheap and easy.