How much R134?

I was going from memory and the rather inaccurate gage on the recharge bottle. I recharged the R-134A in my 96 Voyager last June since the AC wasn't cool enough. I recall reading ~25 psi low side (AC clutch on). After adding the full can (19 oz I recall), it read ~50 psi and the AC now works great. I didn't get all 19 oz in since the plastic valve on the kit had a crack and some leaked. In your case, I would add a 12 oz can. If it helps, but not enough add another can. But don't go over 50 psi low side.

Good to also monitor high-side pressure, but requires another gage. You can get an AC kit at Harbor Freight w/ multi gages and valves. I have one (~$25 on sale), but didn't even bother to use it that time.