View Full Version : 95 FWB Oiling AC compressor

Rob Benham
12-25-06, 10:58 AM
Hi, the supplier's book says put in 8oz of oil prior to reconnecting the pipes. I just want to check that you pour it in the pipe. It seems that it would just block the system up again.


The Ape Man
12-25-06, 07:59 PM
Whenever a component is removed from an AC system some refrigerant oil will be removed with it. 8 oz. sounds like a lot for a compressor but I'm not really sure. This is a good time to add some dye in case leaks have to be chased down in the future. If your system lost the compressor then the expansion tube should be replaced as it has a built-in filter. The system will have to be evacuated of all air also as you probably know. It can then be recharged.

Rob Benham
12-25-06, 08:43 PM
Thanks Ape Man. Yep, the orifice filters were well blocked, I suppose the sheer pressure enabled some gas to pass.

Two things have occurred to me since doing the job. One was that I trusted the guy at an O'Reily's on the quantity and method of putting in the new lube. The tin was 8.5 oz, so it seemed logical that a large car would want most of one helping. Pouring it downhill was easy and made the compressor sound very smooth. But how the !#%! does it stay there and not go round the system like the other junk?

The other thought was that it would have been a neat trick to blow some 134a round the system before vacing out. I think this may have purged some of the water vapor that was in the system.
I had made the mistake of using dye that is mixed with 134, and again trusted the makers. You can see from my blog on a pilot's forum, just how bad this is for the dryer. The inside of the old one is a soggy mess of green goop.

Well, if I have to do this with another car, I'll be just a bit wiser, but the oil is the issue.


The Ape Man
12-26-06, 05:12 PM
Nice post on the other bulliten board.
23" of vacuum isn't correct. Any decent pump should make 28-30". Sometimes the zero on the gauges is off or the needle sticks. I always tap lightly on gauges when looking at steady readings. The important thing is that the system holds vacuum when the valve to the pump is left shut off.
The idea behind amounts of oil in refrig. system components is based on oil continuously mixing with the gas when things are running.

Rob Benham
12-27-06, 01:41 AM
Ouch! I can see how my old eyes misread 23 for 28, but I don't know how the pump failed to pull a good vacuum. I did tap the gauge and it came up a little, but no more than 20 ish. Zero datum looked good.

I guess that I'm still learning and will have another go when the weather gets hot again. Winter here lasts all of a month. I'm back in a week or so. Rob