Hello to the group. I have a 1987 300SDL that was converted years ago by the previous owner from R-12 to R-134. The A/C has finally given up due to the compressor. The cooling capacity inside the car has always been marginal at best here in Houston with our sweltering heat and I want to switch back to the R-12 refrigerant (I was able to obtain some R-12). Anyway the car has the Denso compressor driven by a serpantine belt not the R-4 Delco. I plan on flushing the entire system and replacing the compressor. I ordered a new Denso compressor, expansion valve, dryer and mineral oil. My question has to do with the refrigerant oil capacity. I've looked on the forum here and it only addresses the R-4 Delco. I cannot find the system oil capacity for the Denso unit. I plan on draining the new compressor of all its oil and replacing it with mineral oil.

Also, how much oil do I put into the compressor itself once I am ready to mount the compressor onto the engine? And what about the remainder of the oil once I fill the compressor, place it in the high pressure side of the hose before the expansion valve?

I would appreciate your input.

Thanks

Herb

I've been able to locate some information regarding the refrigerant capacity.

1989-1990 300CE ... R12 35.00 Mineral 7.75
300E ... R12 35.00 Mineral 7.75
300SE ... R12 46.00 Mineral 7.75
300SEL ... R12 46.00 Mineral 7.75
350 SERIES
1991 All Engines R12 46.00 Mineral 7.75
1990 350SDL ... R12 46.00 Mineral 7.75

Its the closest data to the 87 300SDL that I have.

It appears to be 7.75 ounces of mineral oil.

My next question is: Do I pour the entire 7.75 ounces in the compressor? Or whatever I'm able to pour inside the compressor and the rest in the hose just before the expansion valve?

Thanks
Herb

In looking up your compressor....
I assume you have an oil ' tank' on it which can be checked for oil level ?
as compared to the R4 which does not have one....
Does your new receiver dryer say anything about adding oil to it just prior to installation?
If you decide to add oil ... I would put it in between the condenser and the receiver dryer... not slug the TXValve....
For R12 I suggest Castrol premium cold flow mineral oil part number 6912 from Cleburne , Tx... Which is what Carlisle Auto Air in San Antonio suggested when I was buying AC stuff....

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

There is nothing in the compressor instructions about an oil tank. You have to turn the compressor upside down to get oil out during manufacture. Dryer says nothing about how to add oil.