my 94 leaks so i have to recharge it quite often.if you use a dual guage set do not open the high side, the can of freon will explode.i normaly run my high side up to around 220 the low side should be around 32.it will vary some with the temp.its around 95 where i live if its cooler in your area drop about 10-15psi on the high side.
if your not sure about doing it yourself go to a shop and have them vacume all your freon out and refill it with the exact amount it holds, its labeled under the hood.