The Nissan Path

I have a 2000 Pathfinder LE. Once the weather heated up here in Texas a few weeks ago, I noticed the AC wasn't blowing very cold. It's been 95+ outside lately, it seems to be blowing around 78 or 80 in the cabin. The compressor is groaning and there's a crack in the high pressure hose. I took it to a mechanic to verify this, they charged me $50 to check it and agreed with me.

I'm driving from Austin to Houston for July 4th weekend, it's about 3 hours each way. I'm planning to fix this when I get back. But I'm hoping to get it semi-working just for the weekend.

Earlier, I was heading to the parts store to buy freon to recharge it - in my driveway, I noticed the compressor wasn't turning. So I turned off the truck, jiggled the compressor clutch, and turned the truck on again. The clutch started turning, and the low pressure line was nice and cold for about 5 minutes; the parts store is about 8 minutes away. At the store, the clutch was still turning, but the hose was no longer cold.

When I put a gauge on the low side, the pressure seems a little high. So I didn't recharge it. The guy at the parts store said I need to lose some freon, that maybe the mechanic's shop added a little bit of freon to test it, which put it slightly in the red. It was 85 degrees out when we checked it, I found online that for 85 degrees outside, the low side pressure should be around 24-31 psi (and high side should be around 186 - 228 psi). The low side was about 36.

Is there any way I could get this working just for the weekend road trip?

Did the mechanic use some kind of sealant when he added refrigerant? If he added too much, I'd take it back to him and get him to adjust the system to the proper pressure.

The problem with the walmart variety of refilling available is that there isn't anything you can do to remove the refrigerant properly if overcharged. Other than venting to atmosphere which I don't recommend.

4 psi over on the low side isn't really a big deal...but the reading is almost worthless without knowing what the high pressure side is at. That's the issue with quick service AC kits is that they only give you a low-side gauge. If the high side reading is also high, then it could be due to an overcharge. But, if the high side reading is low, it would be an indication of an entirely different problem. Also, temperature isn't the only thing to consider during a performance check (which also includes running the engine at a specific RPM with the fan in a specific setting and driver's window open), you must also take in to account the humidity, which has a great affect on the system's operating efficiency.