AC issue

[Sandro]

Model: 2005 XB/85,000 miles

I have started noticing the A/C not cooling well. Compressor kicks on, no funny noises, belts ok.

So I bought one of those Interdynamics recharge kits with guage and checked the low pressure side, which showed about 35 psi with ambient temp about 80 degrees. I added a tad of R-134a and saw maybe a little better cooling.

Question is: what is the correct pressure? Is there a good chart somewhere specific to the Xb?

Leaving in trip tomorrow to Florida for Sun n Fun Airshow and would like cold air.

Thanks