Just curious as to what experiences anyone has had for cleaning a previuosly used oil cooler. I acquired one with the engine I bought for use in my project and it was certainly functioning with the engine in the aircraft but I want to give it a good cleaning before use again. I'm sure some of the standard approaches would work like using AV fuel or Brake Clean or even good ole Dawn dishwashing liquid but I wondered if anyone has ever sent an oil cooler to a Radiator shop for cleaning and pressure testing...?