My A/C on my 97 Chevy Z71 is not cooling like it used to. I've checked the refrigerant pressures and they seem to be good. I blows kinda cold air but not as cold as I hink it should. We had a 90 degree day the other day and I had to run on hi to stay cool. I replaced the compressor a few years ago and flushed the system them. I also remember replacing a small screen filter where the line entered the condenser coil - wondered if maybe this is stopped up - if I didn't get the system completly flushed??? I also wondered if maybe the evaporator coil could be dirty, acting like insulation on the fins keeping it from cooling??? Just trying to get some advice before it gets really hot.