So my AC Compressor is on and running the entire time (not cycling) but it only blows out cool air not cold air. Radiator fan is running. Low side pressure is at 50 and high side just above 200. Should I add a can and recharge it? How much should I put in?
The system was professionally converted to R134a 8 years ago.

 

You could always give that AC Pro or comparable stuff at the parts stores a shot. Pretty easy to use and it has a gauge on the can to tell you how much to put in or even if it’s safe to do so. I think it even has a little stop leak in there.

 

Just thought I’d add I had a pro recharge mine for like $95 2 years ago, a difference of about $50 compared to the DIY can.

 

I have bottle. It's called avalanche. On that bottle it also says 50 PSI right near the yellow.

 

I'll probably have that done in a week or two.

 

What's your ambient temperature? If you don't have a parallel flow condenser installed, you might be as cool as you're going to get if it's 80+ out.

Your pressures aren't that far out of line..

 

Pressure seems low on the high side and high on the low side. At 80 degree ambient they should be 25 to 275 and 35 to 40.

Looks rather like a bad reed valve in the compressor.

 

I'll have to get a thermometer for the vents and check. It's been 95 to 100 degrees everyday here. I believe it's the original stock condenser.

 

Gotcha. It's been 95-100 degrees out everyday for the last two weeks. Usually by 10 am it's 90 degrees.
Regarding the reed valve, I'm guessing it's easier just to replace the compressor and dryer?

 

Pretty much. It's "possible" to replace a single reed valve, but not much fun, and of course you still need a dryer, maybe OT, full charge, etc., so you don't really "save" much. They're really the weak point of that compressor design. There's 4 sets of them, one per cyl. They usually kind of shred, then that creates a leak directly between the high and low sides, so you get the symptoms you have... not enough "suck" on the low side, not enough "blow" on the high side.

 

Just to note. I drove it earlier tonight, whether dropped to a very humid 82 degrees and with the heat index it felt 88. My ac actually felt cold in the high 80s.

 

There is a lot of room for hot air to get mixed in with your cold a/c air at the firewall vent. make sure it is closing all the way and has a good seal. Also make sure your condenser has a good seal around its sides, (foam seal) so that cooler air is passing thru it, and not around it.

 

Very good suggestion, in a general way; I highly recommend following it; but won't be the cure in this situation I fear. The pressures tell the story.

 

I just saw this. I just went through this with my '88 Camaro. After having the AC system recharged, the AC guy at the repair shop said that while the compressor was working - it was weak and not providing enough pressure to compress the r134a freon to make it cold (the compressor is 32 years old). He recommended replacing the compressor, the accumulator and flushing the condenser. My AC is now putting out cold air!