1992 Mercedes Benz 300d no o-ring seals

FMC99RK

MEMBER
1992 MERCEDES BENZ 300D

Air Conditioning problem
1992 Mercedes Benz 300d Two Wheel Drive Automatic 365000 miles

Hello, Frank

You are asking the following question to the Cars Experts.
I have a 1992 300D 2.5 turbo the air conditioning is not working so befor I take it in to have freon put in I whanted to replace all the o-rings. There are none, I took off lines from the reciver\dryer and there are none.
thanks
frank

1 Reply

DR LOOT

MECHANIC
2,311 POSTS

I am as confused as you, the manual for your vehicle states to follow:

DISCONNECTING LINES & FITTINGS After system is discharged, carefully clean area around all fittings to be opened. Always use 2 wrenches when tightening or loosening fittings. Some refrigerant lines are connected with a coupling. Special tools may be required to disconnect lines. Cap or plug all openings as soon as lines are removed. DO NOT remove caps until connections of lines and fittings are completed. NOTE:All R-134a based systems use 1/2-16 ACME threaded fittings.

CONNECTING LINES & FITTINGS NOTE: Different fittings and connections are used on systems using HFC-134a refrigerant. Ensure all replacement parts match the connections of the system being worked on. Always use a new gasket or "O" ring when connecting lines or fittings. Coat "O" ring with refrigerant oil and ensure it is not twisted during installation. Always use 2 wrenches to prevent damage to lines and fittings.