I know I'm bumping an old thread, but I can't find answers to my problem. My 94 V6 car didn't have working air when I bought it. I was told a recharge kit from Wal-Mart had been put it, but it only worked for a while. That told me it was just a leak. I bought a gauge kit ( which reads high and low pressure ) and some freon. My neighbor has an AC pump that he let me use. We hooked the gauges and sure enough, nothing. We hooked up the pump and let it run for 20 minutes. Then we closed the lines and unhooked the pump, but it held vacuum. With a leak in the system, you'd expect that to bleed off and the pressure to return to zero. We went ahead and put in one can of freon ( 14 oz ) and the compressor kicked on. It was blowing cold. When we unhooked the lines, it was hissing out of the high pressure valve. That explains why we couldn't see the leak with the lines hooked up.
Next day I bought a new valve and installed it after having the freon pumped out. Vacuumed out the system again for 20 minutes. Then added two 12 oz bottles of freon to the system. It was showing 30 lbs of pressure which is within parameters, and blowing cold. We drove the car for the next 3 days and the AC blew cold.
Fast forward to today. I get in the car to drive home after work, and I'm getting hot air. Upon further inspection, the compressor isn't kicking on at all. So I put the gauges back on and both the high and low are reading 45 lbs. No change at all even if I start the car.
Upon further inspection, the car is supposed to hold 2 lbs of freon. I thought the reading on the bottle was fluid oz, but it does say "weight" in front of it. So according to that, the system is 8 oz low. Seems simple enough, just add more. What I don't understand though is, why would the compressor kick on yesterday, but not today with the same amount of freon? Also, does it mean anything that the pressure was reading the same on both lines? Could that be indicative of a different problem?
Thanks ahead of time for any responses.