My '72 GMC had factory air. About 15 years ago when my dad owned it, the pully froze up and fried the belt. As near as I can tell (not knowing anything about ac) the clutch is shot. The pully turns, but the clutch is lop-sided and falls as the pully is turned. Make sense? I can buy a new clutch at NAPA and the manual says it can be replaced without removal of the compressor and, therefore, without draining the freon. The question is this. Is there a way short of looking for evidence of leaks, to know whether or not there is a need to replace more than the clutch? NAPA sells a rebuilt compressor for just a little more than the cost of the clutch, but they also say the book says to replace the other ac components at the same time. And I know from reading this involves disconnecting the hoses and draining the freon. The second question has to do with the operation of the unit. My truck emits hot air into the cab even with everything turned off. If the ac clutch is shot, does this cause hot air to be emitted instead of nothing? I'm not explaining this very well. It doesn't blow the hot air like it would with the fan on high. But at all times, there is hot air coming through the vents. I'm not sure if this is a symptom of a burned out ac clutch or if I have other issues such as relays inside the heater unit not opening the proper gate for cold vs warm air. Any ac knowledgable people out there? Thanks. The truck is a '72 GMC half-ton with factory air and a stock 402.
