AC refrigerant level check?

[RussKincaid]

I see this problem a lot with some of the newer trucks and it's usually pretty easy to figure out. First, watch the A/C compressor to insure when you turn the A/C to max that it turns on and stays on. If not, you have to find out why. The low pressure cut-off switches and wires are always suspect., make a wire jumper and short across the switch. It's located on the the big can by the firewall. Check pressures 30-50 low and 200-250 high are generally regarded as normal. pressures without the compressor running won't tell you very much. Post back with results and I'll try to help you out.

 

[95C1500]

It's a gazillion dollars, at least that's what I charge people

You're a little out of my price range

 

[Coveman]

not sure why you are hating on the diy charging cans? i really like them, i top off all my cars when i have an open can. I have the manifold too, but really the cans get 'er done just fine.

 

[Urambo Tauro]

The cans themselves are not the problem. The problem with using cans to "top off" is the reduced efficiency of mixing fresh refrigerant with refrigerant that has leaked out its smaller molecular components. Failing to evacuate the system after a minor leak leaves you with a diluted charge.

But it wasn't the use of cans that magimerlin was hating on. He's talking about the single gauges that are packaged with them. You need a set of proper manifold gauges to monitor both high side and low side pressures.

 

[kooshball]

Thx!!

I see this problem a lot with some of the newer trucks and it's usually pretty easy to figure out. First, watch the A/C compressor to insure when you turn the A/C to max that it turns on and stays on. If not, you have to find out why. The low pressure cut-off switches and wires are always suspect., make a wire jumper and short across the switch. It's located on the the big can by the firewall. Check pressures 30-50 low and 200-250 high are generally regarded as normal. pressures without the compressor running won't tell you very much. Post back with results and I'll try to help you out.

 

[BIG_KID]

The cans themselves are not the problem. The problem with using cans to "top off" is the reduced efficiency of mixing fresh refrigerant with refrigerant that has leaked out its smaller molecular components. Failing to evacuate the system after a minor leak leaves you with a diluted charge.

When did 134 become a blended refergerant ?

 

[BIG_KID]

not sure why you are hating on the diy charging cans? i really like them, i top off all my cars when i have an open can. I have the manifold too, but really the cans get 'er done just fine.

X2

 

[Shaun Anderson]

When topping off your system with a can be careful not to add to much. You don't want the liquid refrigerant to overflow the accumulator during a long idle period and get drawn into the compressor. Compressor can't handle liquid refrigerant. Holes tend to appear in the case, or swash plate mechanisms grenade.

When I top off I add till I see the low side just start to raise up beyond a steady psi which is correct for ambient conditions temp/humidity. Then I monitor it for awhile at 1,200 rpms, windows down fan on high, a/c on full cold. If pressure is running away, or higher than it should be I recover a little just till the pressure remains steady/correct for ambient conditions. I look to see the accumulator is sweating heavy as well as the suction line going all the way to the compressor.

This only works on a system which has no air/water in it. Any air/water contamination will cause pressures to run away. This is an imperfect method. I could be slightly overcharged or undercharged. Don't want either. It has worked for me though. Haven't observed a premature failure of a compressor yet.

Best is to recover, change the accumulator/drier, pull a hard vacuum for an hr and recharge by weight.