Matt83076

Does anyone know what the correct pressure in psi would be to charge up our AC? I wanted to charge it, but don’t want to risk overpressure and damage something.

Did a search and didn’t find anything. Anyone out there know for sure?

sgmotoring

There is a A/C performance test you can do, but I need to know the out side temperate. The other way is to evacuate the system completely and charge it with 22 oz of freon.

King of the Road

There is no reason to charge the A/C unless it is not cold, but then, that means there might be a leak in the system. I would not suggest to charge it if the A/C is cold.

Sly Raskal

iTrader: (1)

i don't think our systems use freon anymore.

they use some other thing that is "environmentally safe"

dgracer

If it is not cold there is a leak somewhere. You shouldnt have to charge these systems up at all. R134a is the replacement for freon. If you decide to try and buy a can of it, as long as you put it on the low side of the system, you cant really overcharge it. It will just take what it needs. You can even buy a cheap gauge to check it.

ChucksTL_RENAMED

R134A freon, low side should be about 35lbs. pressure.

Allout

Not true - You can overcharge the system.

Matt83076

Thanks for the replys. It does say on the can of R143a that I got not to overcharge the system.

sgmotoring

35 sound too high.

Allout

Pressure will vary based upon temp. Pressure is not a constant. It's like saying your tires should be 32lbs. hot or cold - it doesn't work that way.

SMR Type S

Is your A/C blowing cold? If so, it is not worth messing with. If it is not blowing cold, is your car still under warranty? If so take it to the dealer. The system pressures don't mean much, unless they are compared to ambient temperature, humidity, and interior temperature. If you do not have any experience with A/C, and have no warranty, take it a shop that does A/C work. They will use a refrigerant recovery machine that removes and measures the freon charge. If the system is very low, you probably have a leak. If it just slightly low, and no freon has been added for several years, it can be recharged with the correct amount, as some leakage is normal from the seals. A simple, and more accurate test for proper freon charge on any A/C system is to check the inlet and outlet temperatures of the evaporator (if you can get to them). The temperatures will be the same on a properly charged system. Higher outlet temperature means low on charge, and higher inlet temperature means overcharged. The system should be run for several minutes to stabilize first. If you decide to add freon, be careful, one 14 ounce can may seriously overcharge it.

Chemmech

Buy a maunual?

shmookles

If A/C is not blowing cold. does the warranty cover for the cost of repair for this?