Mercedes: Refrigerant, r 134a, receiver dryer

Question
I have a 1988 560 sec. The air is no longer cool and I would like to recharge it. What refrigerant is in it and will the recharge can(s) you buy from the autostore work?

Answer
Answer:

You have an R-12 system.
No, the R-134A at your local parts store will not work correctly without changing the evaporator, condenser, compressor, receiver/dryer, and all seals/O-rings.

My best advice:
Recover the refrigerant, replace all seals/O-rings, vacuum the system, charge it with Nitrogen and check for leaks.
If no leaks are found, then vacuum the system and charge with R-12.

The system should be good for roughly ten more years of service.

Here are some threads you may want to read on the topic.

Climate Control:
http://www.mercedesshop.com/shopforum/showthread.php?t=142408