sawspa

Have removed my air conditioning compressor, but when I drained it there was next to no oil in it. There was barely enough oil to coat the bottom of a solo cup. So how much should I put in my replacement compressor? Also, what oil is it?

djb383

The replacement compressor should be emptied out as well. U need to find out how many total ozs of oil for your year model....add 1/2 to the replacement compressor and 1/2 to the new accumulator/dryer.

The evap and cond should be flushed to remove old oil so the system will not be overfilled with oil.

sawspa

Dont I have to have some oil in it before or while I drive it to the shop?

djb383

U only need oil if the compressor is engaged. My presumption is u r replacing the compressor yourself. If so, the new/reman comp needs to be emptied, the evap, cond, all lines need to be flushed and the accumulator/dryer and liquid line/orifice tube need to be replaced with new (they r filters)......that way u start out with zero oil in the system so u can accurately measure the amount of oil specific for your year model. Add 1/2 of that specific amount to the new dryer and the other 1/2 to the replacement compressor. That's the way the shop should do it. After the correct amount of oil is in the system and it's all buttoned up, have a shop pull/hold a vacuum and add the specific number of ozs of refrigerant for your year model. There should be a sticker under the hood indicating the lbs/ozs of refrigerant.

sawspa

New accumulator? Really, is it necesaary?

DFlintstone

Quick question....I just messed around with mine, saying what i did would just be confusing, but Djb, or anyone...anybody know anything about that "oil"?
of course I would put Castrol 30W in anything I could...but the AC oil I had left in an old recharge can seemed "bubbley" ??? I got an oz or two in there...

djb383

Did a lot of Google searching/reading....replacing both the accumulator/dryer and orifice tube was recommended because they r both filters and don't want crud from old dryer/orifice tube ruining the replacement compressor. IIRC, new dryer and tube were about $65.

sawspa

SP-20 PAG oil

DFlintstone

THANKS! <PAG OIL (Polyalkylene Glycol) Refrigerant oil made for HFC (e.g. R-134a) systems>

sawspa

If I rent a vacuum machine will that pull the oil out? I thought I read a chart on this site that showed how much oil each part should have in it. Can anyone provide a link to it?

djb383

What year r we talking about? Vacuum doesn't pull oil out. A '98 holds 8.1 ozs total. Measure and pour 1/2 into the new dryer and other 1/2 in the replacement compressor. If all old oil is not removed, u have a chance of overfilling with oil and cooling efficiency will be reduced.

rrich

Mixing oils creates gum - problems - PAG and mineral oil. Even a little bit left over can cause problems.

Unless you've flushed it out and are certain there's no oil left, use ESTER OIL. It's compatible with either type of oil - PAG or mineral oil - and won't gum up. It's slightly more expensive, but well worth it.

If you have the system open look up your compressor on the internet - make and model - serial plate on the compressor.

It will show you how to make a dipstick to check the oil inside the compressor's crankcase - through a big plug on the side.
The crankcase has the bearings and wobble plate, the other end has the reed valves. They don't necessarily share oil except through a tiny hole.
Having one full doesn't mean the other is adequate.

Find the total capacity of oil for your system - add enough in the crankcase till the dipstick shows full. Add the rest to the dryer.

Too much oil is almost as bad as not enough.

Replacing the dryer is a good idea to prevent problems when converting from 12 to 134. The desiccant materiel used for the 12 tends to disintegrate with the 134.
If the compressor self destructed, the orifice should be replaced too - it catches all the shrapnel. It's cheap, depending on the type, rent the puller tool from a parts house. It looks like a sheet metal screw will work, but you'll leave pieces in it. (He He - don't ask!)

sawspa

It's a 99. I was wanting to know how much oil is in just the compressor. When I poured mine out, it was just enough to coat the bottom of a solo cup. Is that about right or is it low. I planned on replacing what came out plus an ounce. I just didn't think it seemed like enough oil

djb383

The oil circulates throughout the entire system....just make sure the system has the correct total amount of oil for your year. The orifice tube is "built-in" the liquid line on the XJ, at least it is on a '98.

rrich

"""""just make sure the system has the correct total amount of oil for your year. """""

Do that without making sure the crank/wobble plate end of the compressor is filled correctly and the life expectancy of the compressor is probably about 1/2 hour. About the same as running your engine without oil.
Many rebuilt compressors come with the dipstick and instructions.

Reading how to make the dipstick from a coat hanger is too hard and complicated for some people. Or is it they get a powerful feeling when they cause someone to ruin something?

What you had in there - the few drops - is not near enough.

You'll see in the diagrams the tiny bleed hole - it's to equalize pressure, not transfer oil. Or take one apart and see for yourself. At least look in your Factory Service Manual.