Originally Posted By: gregk24
Are those A/C recharge kits safe? I have no experience using them, afraid I would do more harm than good.
The professionals here will tell you the only way to get the proper operation from your AC is to remove all the refrigerant from the system and refill it according to weight. But it costs MONEY and unless you have a trusted shop they could screw the job up as well.
If your system is a bit low, which it sounds like it is, you CAN top it off with a couple or few ounces safely without damaging it.
Most importantly is to NOT use a sealer refrigerant or one with oil already in it...Just use PLAIN OLD PURE 134a, which is cheapest too.
You can get a cheap low pressure port gauge set which will do a safe job so you won't overfill it. Also something missed by many DIYers is to purge the gauge set of air BEFORE CONNECTING IT to your low pressure (refill) port. You simply open the value on the gauge hose and let it flow until you get a solid stream of 134a out of it with no air pockets. CRITICAL if you want things to work right and not cause other problems, WHEN REFILLING LESS IS MORE, even if the system is not perfectly filled it is still safer than overfilling it, so stay safe and if in any doubt only fill until the gauge reads at the LOWER end of the green area, as long as you get decent cold air STOP! you're are done!