Refrigerant can gauge reads between “hi” & "danger zone" when compressor turns

[Cstoliker]

The AC worked great last summer on my 95 XLT. There was a small leak somewhere and I had to charge it once during the season but it worked well.

This summer I noticed the AC was barley cutting it first time the temp approached 80. The compressor was turning on, but I though it could use a charge. The gauge on the refrigerant can reads high when compressor is off and goes into "danger zone" (red) when compressor is on.

I just wanted to some input on this before I replace the compressor. Admittedly I have limited knowledge of AC systems beyond how they work on paper. Am I right in thinking it is a bad compressor that’s leaking between high and low pressure sides. Or could it be a simpler problem like a clogged expansion (orifice) tube?

 

[Blee1099]

Junk that dummy gauge and get a set of manifold guages that display high & low pressures. Low pressure should be under 40 and high pressure should be 2.5x the ambient temperature. If you dumped an entire can after charging it initially earlier this year it may be overcharged.

 

[zkt]

I`ll second that advice on the gauges and agree that you probably overcharged it. Full charge is 22oz and a few low can make a big difference in output air temperature- so you may be way over. Over charge it and it starts warming up again. Good idea to monitor both the output air temp and can fullness as you charge.

 

[Cstoliker]

I did not charge it this year. I put the can on it thinking it needed a charge and noticed the high pressure. I believe the presser is to high to for a can to over come anyway. Perhaps I overcharged the system last year before winter. Should I discharge the system and re-fill?