I had made one out of an small R-12 tank. I would put about 2 or 3 quart of ATF in it. I also had a line that would plug into the main oil gallery and then I would apply air pressure equal to low engine oil pressure and with the pan off and a good trusty light I would see where I had abnormal leaks. The red oil is fairly easy to see and I always figgured it was a bout the thickness of hot engine oil