My Gibson Refrigerator worked perfectly for over 30 years. Then a few months ago when I returned from vacation the freezer temperature was high. An appliance technician said it was low on refrigerant, so he added a piercing valve putting R134A into the system, saying this was compatible with R12. He eventually stopped adding, saying he was afraid the A/C current was getting too high (now 3.33A). He did not take any pressure measurements, charged my $150 and left.

For the next few days with the freezer nearly empty I would check about once an hour, and saw freezer was either 0F or 50F. I put an open 3 gallons container of water in it to give some mass which helped, but checking further found that the defrost timer contacts were burned preventing it to cycle properly. I replaced the defrost timer myself.

The freezer now stays cold, but every time the compressor starts I hear what sounds like water dripping/running, but its coming from the refrigerant return line to the compressor, not the defrost drain lines. The refrigerator had never made this sound before. A shifting movement sound "thong?" also occurs at the heat removal coils on the back of the refrigerator each time a few seconds after the compressor. The compressor stays too hot to the touch even when it's not running, and seems to be cycling too frequently.

I'm wondering if there's too much coolant causing the compressor to overheat, the new dripping sound, and the fast cycling. The unit is old enough that I haven't been able to find what the low pressure side should be.

Any thoughts?