AC Compressor Relief Valve

[Number4]

Looking to see if anyone has a quick answer.

Started up my ‘94 which had been driven in 94° weather for 10 miles. I parked in the shade and went into a store for 30 mins.

I returned to my Ex and fired it up (AC was on). It rough idled as it does, often, after having run then been shut off and started again. Then I heard a rushing if air sound and there was a “cloud” coming out if the drivers side hood on the side. At first, I thought it was coolant, but realized it was refrigerant. Based on the spray pattern of the refrigerant, I’m guessing it came out of the compressor’s relief valve.

A quick read online suggests that a bad fan clutch could cause this. Though the car was only idling for a few moments before it happened.

I would note that the entire AC system has been replaced. The car then sat for two years and the AC leaked out. I put a vacuum on it, refilled it and it’s been running since, though I’ve had the suspicion that it’s been slowly leaking refrigerant.

 

[BeartoothEx]

I've done some DIY AC work, and I'd say the problem here is more likely to be an internal blockage than too little airflow over the condenser. I haven't dug into the workings of my Ex's AC; that said, it looks like there are two pressure switches - low side and high side, and the high side switch should have cut it off before the relief valve blew. Maybe it is a combination of that switch failed and not enough airflow, or if it were overcharged, that could be a contributing factor too. Is your suspicion of a leak based on a loss of performance? If so, it could have been a gradually building blockage that finally got to the point where it blew. Hard to say for sure, but I'd definitely check the orifice valve and see if there seems to be any resistance to flow through the condenser. Nothing you've done with it sounds like it'd cause any problems, but it sounds like more than a bad fan/clutch. I'd R&R the orifice valve, make sure the condenser is ok, and look for any contamination or internal issues before trying again.