[jlex]

There was a post a week or so ago about someone testing his oil cooler. Turns out, coolers experience a lot more heat/pressure than the 15lbs you're using to test. I might be wrong, but it sticks in my head that they were saying testing should be done to around 60lbs. As I recall, they sent it to a radiator shop for testing, but the consensus was even the radiator shop wasn't using enough pressure to test it properly. I believe it turned out to be a leaky main seal that was throwing oil that made it look like a bad oil cooler.
Maybe you can find that post...