Recharged my 1996 850's A/C for $25 and 20 minutes

[mcp]

Background info: 1996 850 with 209,000 miles. I've owned the car since 1998 and 25,000 miles. I had to charge my a/c once before about 5-6 years ago when it had these same symptoms.

My A/C was sort of working when the outside temp was 80 degrees or lower, but the hotter it got outside, the more warm air blew from my a/c vents. My A/C compressor would cycle on and off very quickly, a symptom of low refrigerant. This afternoon it was 98 degrees and my a/c was hardly working.

After reading up on charging my 850's A/C here:
Volvo Air Conditioning Problems and Fixes

I went to Wal-Mart (Yes I know, evil giant corporation, but I was hot and it was close by.) and bought one of these for $16.97:
R-134a Trigger Charger and Gauge
I also purchased a can of r134a for $7.00. I bought straight r134a. No "leak sealers", no "UV Dye" and no other additives to gunk up my a/c system. I found it on the bottom shelf under all the other cans of r134 with "Arctic Freeze" and with "Sub Zero Chill" additives. I was tempted by the Arctic Freeze with NASA technology, but it had "system safe leak sealers" and I didn't want to chance gunking up my a/c system.

I used a 19mm wrench to unscrew the cap marked 6 nm from the low side a/c port near the windshield washer fluid refill pipe and popped the refill hose/gauge on it. When I looked at the gauge at this point, it was in the red danger zone. Then I started the car and turned the A/C on max and made sure the compressor had kicked in. (I had some cool air coming from the vents and I heard it when the compressor kicked in and put a load on the engine.) I watched as the gauge went down below the green zone showing the low pressure side was going too low and needed some refrigerant added.

While the car and the a/c was running, I screwed the can of r134a to the refill hose, squeezed the trigger and rocked the can back and forth as much as I could in the tight quarters. (Watch out for the spinning power steering pump pulley and the alternator underneath it. It would be great if the refill hose was a foot longer.) Squeeze and rock for a few seconds, then let go and check the gauge. I was aiming for 35 psi or right in the middle of the green zone. As the r134a flowed in, the can got cold. (Make sure the compressor is running before squeezing the trigger. If it is not running, you can bypass the low pressure switch as referenced in the threads linked above.) I quit when it got to 35 psi right in the middle. The gauge face had some molded in marks like a V with a line in the middle which corresponded to 35 psi, so I lined up with those.

Now my a/c seems to be working normally again.

Thank you Matthew! I have found and used other good information here, but none that made my car more comfortable.