Ross78

I recently installed a new compressor, accumulator, and hoses. I am converting the system to R134.

How much oil do I need to add?

The kit has oil in the cans, but it states if the system was opened and components changed you have to add oil. The kit adds 2 ounces.

BigBadRed

I just did my 79 TA (AC compressor would probably work on a M1A1 tank) the compressor seems very comparable to my 76 stingray. It required 10oz

--marc

82X-FireVette

If you installed a new R4 "pancake" compressor, they take 6 ounces. The accumulator will absorb about 2 ounces, the evaporator will retain about 1 ounce and the condensor will retain about 2 ounces. The total is 11 ounces of oil required for the whole system. :chevy


[Modified by 82X-FireVette, 8:49 AM 8/8/2003]

Rockn-Roll

Did you have the system flushed? The condenser could have something like 4oz and the evaporator maybe 2oz at most. It's a good idea to flush it to get the old oil out. I do hope you got the POE (Ester) oil and not the PAG (Mineral) oil. PAG is not compatible with the old O-rings and oils so if you are going to use PAG then everything needs to be flushed and all new O-rings (the blue ones) need to be installed. You will also have to make sure that the new accumulator has the blue O-rings or it will leak before the year is over. you can optionally use the green O-rings, but the black ones will leak if PAG is used.

The correct oil to refrigerant mixture is 1oz Ester oil to every 6oz of R134a refrigerant...I believe PAG is the same mix, but I'm not sure cause I use Ester since I'm using my original A/C compressor. This ratio will keep the oil suspended in the R134a so it can circulate and keep the compressor lubricated, any more than that and the excess oil will just pool up somewhere, any less and the compressor may not get enough lube. It doesn't hurt to have a little oil pool somewhere in the system so err on the side of too much oil and you should be fine.

I poured 3oz of oil into the compressor and 4oz into the accumulator then used a 2oz oil and 12oz R134a charge followed by one whole 12oz can of R134a into the system and then 1/2 each of 2 other 12oz cans for a total of about 36oz R134a. The shop guys said that I added too much oil. The A/C system works better with less oil cause excess oil could sit in the accumulator and cover the dessicant and keep it from working. You will probably only be able to get 40oz of R134a into the system at the max, though more like 36oz like I did. So, you only need about 6oz of oil. I would pour 2oz into the compressor then 2oz into the accumulator then use a 2oz oil + 12oz R134a recharge can when you begin filling. It would not hurt to add another oz into the compressor if it will fit. My compressor leaked some of the 3oz out when I installed it. I don't think I have any less than 6oz of oil in the system. But, 10oz or especially 11oz seems like way too much. With the R12 system which could take about 50oz it would not be too bad with 10oz, but it would be overkill with just 40oz of refrigerant. I'd say the best range would be 6oz to 8oz...anywhere in there would provide an optimum fill with R134a.

Somewhere in the forum I posted more details on what I did to get my A/C going like it is now, but I couldn't find the post when I searched for it. My air vent temp reads as low as 40ºF on 100ºF days, so I must have done something right. I wish I had replaced my blower motor with something more powerfull when I replaced my heater core though, cause the air warms up a bit by the time it hits my face.



[Modified by Rockn-Roll, 10:21 AM 8/8/2003]