Another A/C Question!
 

1989 300E

This is an original R-12 system. Held it's charge until 3 years ago when a relative who borrowed the car for an extended period of time took it to a Mercedes dealer for a A/C service. They said it cost about $200 back then for the service. The system needs to be recharged again.

In past years, I have recharged older cars with R-12 systems (not Mercedes) without problems. However, I noticed the valve fittings along the hoses (both high and low) on this Mercedes are like the newer R-134-a systems (push type vs screw type). I am not aware of the system was converted to a newer R-134-a. The receiver dryer looks original with a sight glass and nothing looks like it was replaced. I noticed a valve on the compressor itself is an older screw type fitting that fits my R-12 hoses. I am confused...........

Questions: Are the valves along the hoses on this old 1989 300E Mercedes the push type vs screw type or does it appear they changed three years ago when the car was serviced?

What is that valve on the compressor itself? Is that a low pressure fitting where the recharge can be performed?

I doubt the system was converted to a 134a based on what I could see and the fact that my relative said it only cost around $200 for that recharge 3 years ago. I may have to call the dealer for an answer or just take it in to a certified A/C mechanic.........

Comments are welcomed!

Confused Mercedes owner!

By law you must change the fittings when you convert a system - sounds like it was converted.

I agree. I can't imagine why the fittings were changed if it was not converted. And to answer your question, your car came from the factory with the R12-style fittings.