Is the blow off valve on the back of the ac compressor universal? The replacement compressor on my '91 runs fine, cools fine. Saturday I was doing some clean up on the truck. I started it up after sitting for 4 days and within 10 seconds of startup I heard a very noticeable under hood hiss. I stepped around to see a fine mist coming from the right side of the engine but it quit before I could see the source. I started it again and again within 10 seconds it happened again but I got around to see it was coming from the back of the compressor. It was the blow off valve. This is an off brand replacement compressor with less than 8,000 miles on it. Uncommon failure I guess?