0

I have a/c gauges and a vacuum pump and the refrigerant has been removed from the system. I had to replace the high side connection and replaced the Schrader valve on the low side port. I am going to vacuum the system and confirm there are no leaks. I am wondering if I need to add this pag 46 oil charge and if so do I do it before or after putting R-134 in system?

1
  • Welcome to Motor Vehicle Maintenance & Repair! Commented Jun 11 at 10:51

1 Answer 1

0

Is your '95 r12 or r134a? If r12, the system should be completely flushed of old mineral oil, compressor removed/drained/flushed of oil, receiver/filter/drier and orifice tube (if used) replaced, then refilled with pag oil. Oil should be poured into openings, remainder in the compressor before reassembling everything for system evacuation. Use new seals wherever fittings were disconnected and lube with mineral oil, not pag oil.

If this system is r134a, oil is added only when major parts are replaced (condenser/evaporator coil, filter/drier, compressor. If this system was left opened for some time, either replace the filter/drier or run the vacuum pump about an hour or more; this allows any moisture in a vacuum to boil immediately for removal to restore the dessicant's ability to continue absorbing minute moisture in a sealed system. It's not recommended to add oil if a system didn't lose any as it would decrease the total volume needed for refrigerant. If an ounce or so of oil is added, pour it into the compressor suction side, then rotate the compressor by hand several times to help distribute it before evacuating the system. Also, while the system is open, add a 1/4 oz/small bottle of dye. A little messier but one can of r134a with dye is an alternative. Once evacuated, be sure a vacuum holds after shutting off the vacuum pump. Install a can with engine off, then startup; there should be sufficient pressure in the system to turn on ac and add additional r134a to capacity. Don't use any sealer.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .