Reviving a 44yo ac system tips ???

Hi,

Sounds like you have many of the needed issues covered. Did you replace the shaft seal in the compressor and the seal housing O ring? You should have 8 to 10 oz of oil in the compressor.

The o rings should be HNBR types and are frequently green in color for use with R-134A. The o rings should be coated with a drop of 525 A/C mineral oil are you assemble them. You can also use something called Nylog, blue tube for R-134A.

The muffler are sound impulse suppressors. You should flush out the evaporator and condenser with some A/C flush solvent and blow out with plenty of compressed air. You want to get any old oil out of there as the old oil doesn't get along well with PAG. Your new receiver/dryer should be the last thing you install in the system as you close it up. Then connect your gauge set and pull a vacuum down to -29 inches and see if it will hold that vacuum. I usually let it sit overnight. Then charge your R-134A into that vacuum. Start with about 75% of the R-12 charge.