Tallguy67

I just need a bit of A/C help. I have read most of the current threads on A/C recharging so I won't go back over all of that. My A/C hasn't seemed quite as cold as I expect / remember. I just tested as per the FSM. At an ambient air temp of 73F I am getting chilled air about 48F. That is pretty close to spec so I am tempted to leave well enough alone. One thing I did notice was that my high pressure line was really frost while compressor was running. If I remember correctly, an icy high pressure line is a symptom of low refrigerant volumes. Any thoughts on that? I don't have a good set of high and low pressure gauges yet, just the low pressure gauge that came with the recharge kit. One final question, is the low pressure port the one right beside the turbo and really close to the condenser? The other port is by the passenger battery and it looks like the high side but I really don't want to guess and wreck something. Thanks all.

toms73novass

Yes low pressure is near accumulator (turbo area).

If you are getting 48 chilled air, that seems pretty close. The general rule of thumb is 10 rise from refrigerant temp to evaporator and 10 rise from evaporator to air. You don't want evaporator to get too close to 32 because then it will ice up and you will notice the ac temp rise because air will not flow throughout the plugged evaporator.

With out gages it's tough.

Was the ac working before you added the refrigerant ?

If it was too low it could have let air in the system, which will cause havoc.

high bid

I recently added 1 can of freon...vent temp is 50* on max cool going down the hwy. No gauges used so I guessed at it.

Tallguy67

I will buys set of pressure gauges before I go further. I am 99% sure I am just low on coolant but gauges are way cheaper than a new A/C system. I haven't added any refrigerant yet, so I have not introduced air into system.

Busboy

When adding freon you must bleed the line with freon prior to opening the system, this ensures that only freon enters the system.

toms73novass

Good point! A brief release of refrigerant is acceptable by the EPA for the purpose of line purge.