Replacing my 92 legacy calsonic compressor with an ebay bought one. No oil in compressor or I should say very little. I've been reading that you drain the oil and replace oil drained but since the oil was probably drained for shipping purposes I don't exactly know how much oil to put in? I've read ester is best for converting to 134a from r12 and the amount on the compressor says 8.5 fluid oz's. That seems alot to me. Also receiver dryer I am replacing, most say 1 oz of oil? well if any one knows exactly how much and to fill in the suction side? and if I should add once installed or before, then I'll have a shop pull a vac. I didn't have a compressor meltdown just seem a little tired. Any help would be great.

By the way because of this forum I've fixed my timing belt, horn, cruise control, windows and keyless. Thanks in advance.

I know I should and will post this on subura stuff for sale but This pretty much stays on subject. When I ordered the compressor I got sent a zexel for a 96 I beleive and the junkyard said to forget about it but it did have a 180 day warranty, if anybody's looking for that part and interested I can post pics to see if it's what you need.

Taking a jab at this, I found the first site that I think I understood? 3,2 oz to compressor and between 0.5-0.8 in receiver dryer, sound about right?. I'm beginning to think the 8.5 is for oiling the complete a/c system?

There used to be an Endwrench article about how to figure the oil. I forget exactly what it said, but I think the 8.x fl. oz. was the total amount of oil in the system. Then it had some estimations you could make, since it is not really practicable to measure the amount of oil in the system. Such as so much for a compressor replacement, so much for the receiver/drier, stuff like that. I don't think you're supposed to mix the PAG and ester oils.

 

Subaru had a 12 to 134A conversion kit available for certain years/models. Because I think the expansion valve is different too between the refrigerants.

The earlier year calsonic compressors took a lot of oil, around the 8 oz's you mentioned. The newer ones took less, around 5 oz.

 

I've learned over the years that AC work unfortunately is not an exact science, so whether you use 5 oz or 6 oz....chances are the AC will still work. I would probably recommend putting about 5-6 oz of oil in the compressor and another 1 oz of oil in the receiver drier.

 

Regarding the oil type, mineral (used on R12 systems) and PAG (used on R134a) systems are not compatible. Esther oil is compatible with both, but does not lubricate very well. When I did my R134a conversion I used esther oil initially and ended up going through 2 used compressors. When I finally bought a new compressor I used PAG 100 oil. Assuming you haven't already done the work, I'd suggest flushing the system out and using PAG 100 oil.

 

There is a Haynes HVAC book that is very good and lists oil, refrigerent amounts, & pressures for a variety of vehicles. I'd defintely recommend it if you're doing your own AC work.

 

http://www.amazon.com/Automotive-Heating-Conditioning-Systems-Manuals/dp/1563923815

Here's the thing. The compressor has a tag on it that says use pag 90 oil,... should I use pag @ 8.5 fluid oz as the tag says? will it work with r134a? I'm thinking if the oil is compatible with 134 then I should use that instead of ester? I never read so many conflicting reports on refrigeration oil? Always a challenge isn't it?

Thanks for yours and porcupines responses, I really appreciate the help!

I would go ahead and use the PAG oil.

 

Mineral oil is typically used with R12

PAG oil is typically used with R134a

Esther oil is compatible with both R12 & R134a

 

It would be best to flush the system of any of the old oil since it's probably mineral based oil (for R12 systems)

 

Did your old original compressor say to use PAG oil as well?

 

Also, you probably won't find PAG 90 at the parts store, but you should be able to find PAG 100. That's what I've used in all my setups and it's been fine.

I just happened to find this while looking for something else so I thought I'd add it to the thread:

 

 

I found some of the endwrench articles for the retrofit but it wouldn't let me attach them.