I am in the process of renewing the ac system (85 300TD wagon) - All new components, hoses, exp valve, parallel flow condensor, compressor, evaporator. What kind of oil should I use? (To coat o-rings, put in components) Also what quantity is necessary?

Thanks Steve

Use regular mineral oil. 8 ounces if you have replaced the r/d and flushed everything clear of oil.

For coating o-rings, mineral oil will get the job done, but there is a product called nylog that is especially for this purpose and works great.

Good luck,

It may not seem like it... but the inside of an AC system is a high stress environment.
You want the very best you can find ( cost no object )
I suggest Castrol Refrigeration oil ( premium Mineral Lubricant for R-12 A/C systems ) Viscosity 500.
I have posted pictures of this plastic container on another thread....

Larry, my AC guru in San Antonio says that nylog is simply the AC refrigerant ' dried' a little... to give it more body.... so one needs to match the color (available in at least 2 colors ) Nylog to the system just as one would the oil .....

Thanks for the replies - Is this oil okay for either R-12 or 134?

Only for the R12.
I am sure they make stuff for the R13a but I don't know about it...

Mineral oil is only recommended for R12-for R134A you need polyolester(POE) oil-I'm not sure about the benz, but friends of mine have been running MP34 and R409A in domestics with original mineral oil compressors with no problems (or those aggravating expansion valve replacements)

__________________
1982 300DT 190K (Diesel Purge + synthetic oil=smoothness at last!!!)
2004 Ford E-350 6.0 L PSD 227K
2006 Dodge Ram 3500 SRW HO Cummins 4X4 48RE 42K (brute force tow vehicle)
2005 Scion xB wife's rolling pop can
1993 GMC Sierra C3500 6.2 142K

Only for the R12.
I am sure they make stuff for the R13a but I don't know about it...

Call Trey at Carlisle Auto Air in San Antonio to find out the lowdown...