I don't think that's the right approach. If you need to add refrigerant, you have a leak. Therefore, find and fix the leak first.

 

Are you sure it's low? Did you have it tested? As sd said if its low you have a leak and you'll just be recharging again in a short time.

As far as what one to charge from, I'm not sure I've never done it myself as I don't mess with refrigerant. I'd venture to guess the low side, as I would think the high pressure side would blow up the can. If my memory serves me correctly from my schooling days the fittings are different to prevent hooking up to the wrong fitting.

 

The best thing to do is to post your high-low pressures and try to figure out what's actually wrong with the system. If you post pressures we can try to help.

 

Well the ac works fine the air is semi cold but not hot like as if it was broken. I just want it extra cold. I only see the high line with the H not the low line :/

 

I suggest troubleshooting by making sure the cabin filter is clean, then checking actual pressures. Do you have a gauge setup, or can you rent one?

 

Have you cleaned the condenser, changed the cabin filter, and made sure the compressor is staying on when its supposed to be?

 

Dont just fill up. Do it a the right way.
Check the pressure on both high and low. Put a vacuum in the system and check for leaks. Replace parts if needed.
THEN add refrigerant to the low side. Amount needed is on a sticker on the condenser.

 

I got a kit so I'll check the pressure when I get the gauge in the mail. Thanks guys!

 

OK great.

For the 2,0L cars the low side pressure should be between 127 and 196 kPa while the high side pressure should be between 1471 and 1667 kPa, at 30 to 35C ambient temperature.

 

This is where the low side service port is on my 02' WRX. If you are going to try and charge it that is where it should be done from. Really a/c systems should be service with a machine like I use at work everyday. They are very expensive but it the only way to know how much freon was in the system and how much you are putting in. The system can be damage if there is too little or too much freon. If you have any other question I will do my best to answer them.

 

Thanks guys. I got the car checked and it didn't have a leak so the mechanic just added some cause for some reason the gauge I have wouldn't stay it came coming off the hose.

 

Odd, I wonder if it had ac work before and wasn't charged properly