Automotive Air Conditioning Information Forum

I’m recharging a 1992 Ford F-250 Diesel with R12. I had a Ex Ford Pro Mech do it a couple of years ago and it was a slow waste of refrigerant. I’m replacing the condenser (leaking) and accumulator and orifice tube. My questions are:
Oil is Mineral (Ester)??
How do I determine how much oil to add??
Ive been told to pour any oil out of old condenser and accumulator and add same amount??
If I pour it into new parts will it distribute to where it needs to be??
Would it be wise to flush system and how?

jthearne wrote: ↑Sat Aug 28, 2021 8:53 am I’m recharging a 1992 Ford F-250 Diesel with R12. I had a Ex Ford Pro Mech do it a couple of years ago and it was a slow waste of refrigerant. I’m replacing the condenser (leaking) and accumulator and orifice tube. My questions are:
Oil is Mineral (Ester)?? How do I determine how much oil to add??

If you're staying with R-12, mineral oil is correct. POE (ester) oil is sometimes used when converting a system from R-12 to R-134a if in doubt about whether all the mineral oil has been removed from a system. In this instance, you'll be starting with a clean and completely empty system before adding the correct amount of new mineral oil.

The specs that I have for your truck indicate 44 ounces net weight of R-12 and 10 fluid ounces of mineral oil unless you have differing specs on an under-hood decal, which would take priority.

jthearne wrote: ↑Sat Aug 28, 2021 8:53 am Ive been told to pour any oil out of old condenser and accumulator and add same amount??
If I pour it into new parts will it distribute to where it needs to be??

After emptying all the old oil out of the original compressor, flushing it a few times with new mineral oil only, and solvent-flushing the original evaporator, as well as lines/hoses without mufflers (those having mufflers will have to be replaced), I would distribute the oil as follows: 1.5 ounces each to the flushed and thoroughly dried evaporator and to the new condenser, 1 ounce to the new accumulator, and 6 ounces to the oil-flushed compressor.

jthearne wrote: ↑Sat Aug 28, 2021 8:53 am Would it be wise to flush system and how?

To get out all the old mineral oil, I would flush the original components as described above.