AC system conversion

[DOCJBK]

I have a 1987 560 sl and I am about to change my ac compressor and drier. I already installed the new expansion valve. I want to convert it from R12 to R134. What does it take to convert the system over to the newer refrigerant? I have the rebuilt compressor and new drier waiting to go in

[POS]

Nothing as long as you have the new compressor, drier, and expansion valve. You'd be best to flush the rest of the system (not required), then vacuum it, then pump it full of R134.

[Deltacom]

Originally Posted by DOCJBK

I have a 1987 560 sl and I am about to change my ac compressor and drier. I already installed the new expansion valve. I want to convert it from R12 to R134. What does it take to convert the system over to the newer refrigerant? I have the rebuilt compressor and new drier waiting to go in

According to this video the conversion would appear to be relatively unexpensive and easily done by any DIYer

http://www.id-usa.com/video/redo/fullvideo-high.wmv

[sgaar]

Well, unfortunately it is not that easy. You will have to vacuum down the system if you want it to run at optimal performance otherwise you will have a mix of coolant and air in the system.

But one thing I found interesting is the change of the service port connections. Would it be safe to say that if you have the new quick connect/release the system have been converted? Would that be true on an ’87 560 for example?

[ScottinSoCal]

Originally Posted by sgaar

Well, unfortunately it is not that easy. You will have to vacuum down the system if you want it to run at optimal performance otherwise you will have a mix of coolant and air in the system.

And flushing the system isn't optional. The R12 originally in the car used mineral oil as a lubricant, R134 uses synthetic oil, like PAG. They're not compatible and if combined will damage your system.

But one thing I found interesting is the change of the service port connections. Would it be safe to say that if you have the new quick connect/release the system have been converted? Would that be true on an ’87 560 for example?

The only way to really tell if the labels haven't been changed is to have the gas sampled at an AC service place.