any advise on R22 home ac charging pressures?

Answer 1

Too many variables to guess what the pressures SHOULD be. 65/210 is as normal as 78/330.

You want two things to be correct at the same time, the SUPERHEAT and the SUBCOOLING.

With correct superheat you should have (after at least five minutes) a cold sweating suction line. It should sweat TO the compressor. There should be no sweat ON the compressor, but the suction line should be sweating up to it. The top half of the compressor should be warmish, not hot. The bottom half should be 'kinda hot' (you can put your hand on it but you'd rather not).

With correct subcooling you should have a liquid line that is slightly warmer than the outside temperature (about ten degrees warmer as the previous answerer says). Touch some metal that's in the shade with the back of your nuckles and then touch the liquid line. If it feels the same, you might be over-charged. If it's significantly warmer, you might be under-charged. If you can't get them right at the same time, default to correct superheat.

All of this assumes somewhat 'normal' operating conditions. 72-82 on the inside and 85 to 95 on the outside.

Getting freon levels correct is an art.

Answer 2

R22 Charging Chart

Answer 3

Depending on the machine, the super heat should be between 8 to 12 degrees, and the sub-cooling 10 to 20 degrees.

Check your enthalpy chart to verify your specific charging parameters.

Keep Kool

Answer 4

If you have a hose that is supposed to hook up to the low side service port, then that is the only port it will hook up to. The high side service port is much smaller than the low side. I had recently read on the internet that the low pressure fitting is located on the compressor itself. There is also a high pressure fitting there as well. The low pressure fitting is supposedly the one closer to the drive belt. At any rate, the hose you have should only work with the low pressure port. (But im not too sure how accurate that is...I usually work on GM vehicles.)