mark79,80

The A/C on my 1980 was low on Freon R12 as the compressor kept
cycling and the low and high side pressures were not in spec.
I do notice some oil on the compressor and under the hood so suspect
Freon is being lost from the front seal of the compressor.
I used two 12 oz. R12 cans to bring the Freon to fully charged as measured with gauges.
I also put in two 2oz. oil charge cans. I used two as after the first
one I noticed there was still oil in the can, so figure that with the
two cans at best 3 oz. of oil was added.

I only use the A/C occasionally each season, and the last time
I added a can of R12 was in 2004. In 2002 I added a can of
2oz. oil charge as I noticed the oil under the hood even back then.

Question: Was it a good idea to replace the oil in the system that
has been lost or could I cause problems by having too much oil?

1977L48

the problem with just "adding a little oil" is that you do not know how much you lost, it would be like walking out, seeing an oil puddle under your car and adding a qt of oil without checking the level. ive seen A/C systems so full of oil they only would take 3oz of refrigerant. I would say if you have the correct stuff, pull down the system and check how much oil comes out.

Marlin

Chances are you are not losing that much oil. I would not add anymore. Oil spreads out so it looks like there is more than there is.

REELAV8R

The extra oil displaces freon that should be there. This will make your A/C less efficient, so it won't be as cold. That's bout it unless you fill the system with oil.

mark79,80

If the Freon in the system was removed into an R12 recovery machine,
how would you measure the total oil? Would it all be contained within
the compressor? Don't plan to do this but would like to know for
future service.

chevymans 77

no the oil is distributed throughout the system, some in the
compressor, evaporator, condensor and accumulater. in all the total system holds in the area of 6 oz.

mark79,80

Thanks, that is what I thought.

budco

Mark, regarding the question about how much oil is lost when you recover a system, there is a container that is used to drain the oil in and you can measure it.
I take care of 30+ delivery trucks and they all have a/c. We usually go by adding 2 oz of oil whenever you change one of the major components (compressor, evaporator, condenser or dryer). I would think 2 oz of oil would have been more than enough. If you need to add freon again, I personally wouldn't ad any more oil.

lvmyvt76

you do know that that oil will ruin the fiberglass hood! Get the compressor fixed is the Best fix to do. You are licensed to use R-12, RIGHT??? If you are, then you should know the answer to this problem.