I know it has been a hot summer so far (95-100* days) but my a/c doesn't seem to be cooling as well as it should. It is cool, but not cold. I bought a can of it and a gauge today at NAPA and my buddy who works there checked it for me. He attached the gauge and it showed that it was full and wouldn't take any more before going into the "warning" and "danger" areas of the gauge. The truck is a '98 with almost 111k on it so should I let it out and replace it with new R134a? I don't know what else to do to make it cold like it should be.
The condenser doesn't have any bugs or other gunk stuck to it either so I doubt that is the issue.

 

The refrigerant doesn't wear out, so if it is full simply exchanging it won't fix the problem.
Check your clutch fan for proper operation. You need good air flow across the condenser to shed the heat, if you have a screen front or lots of bugs in the condenser clean them offand try it.
Are you using the Max A/C or recirculate setting?

 

I haven't checked the clutch fan so I'll have to do that. I do have an aftermarket grill but it is less restrictive for air flow than the stock grill. It is a billet grill like this one. http://shophyperformance.com/cart/im...mb/17-412t.jpg

I use the Max A/C setting as well.

 

rabbler's not referring to the grill, he's talking about the A/C condenser behind the grill. If you have lots of bugs in the fins of the condenser, it plugs it up a hose or pressure washer works wonders. Also, if the fins are folded over from damage, that restricts the system too. they make little "combs" that you can straighten them out with. try a hardware store and look for one that you can use on the home window A/C units.

If you really want cold air, you can wire in an electric fan that pushes air through the condenser.

 

If its a hot and humid day your A/C pressure will be higher than normal. It's possible you could be a bit low on refrigerant even if the gauge says it high.
Even with professional equipment hard to recharge on humid days. Try hosing down the condenser with cold water and rev the engine to 1500 rpm while you add R134.
On the other hand if the system is OVER charged (yes it's possible) you will have poor A/C performance.
The only way to know for sure is to suck it all out and add the proper amount of refrigerant (approx 2.1 Lbs I believe)

Please don't just empty it to atmosphere if DIY. R134 isn't Ozone safe, it just not as bad as R12 was.