Convert A/C coolant?

[OldGuard60]

Should I convert my 71 280SL A/C from R12 or should I leave it original?

[BHap]

If it still works, I’d leave it alone. If you need to change the compressor, you may want to consider a Sanden conversion - and even then, you can keep R12. To make a change to R134 I think you need to change to a parallel flow condenser, install a new drier and flush the rest of the system. My 70 280SL has had the same R12 in it for the last 20+ years and still cools ok.

[Peter]

For conversion you als need to change the rubber hoses. So it's a mayor operation.

[OldGuard60]

Thanks for that.  Do you know where I can find R12 and how many cans do you think it will take to recharge it?

[mdsalemi]

R12 is available on eBay.

Plenty available at about $50/can.

Better ensure your system doesn't have any leaks first!

[Peter]

Duracool 12a is a good replacement in Europe, I don't know if it is available in the USA.
Given the low environmental impact of Duracool 12a, the use of this refrigerant for
service applications is not yet limited: this refrigerant will therefore remain available for an
indefinite period of time in order to be able to continue to maintain existing air conditioning systems. Filling an old R12 installation with Duracool 12a can therefore be seen as a sound "long-term solution"

[OldGuard60]

Yep.  Any idea on how much R12 I should buy?

[Peter]

No, i don't know, but the airco specialist might.
I use, after complete overhaul r134a. 800 gram was loaded then.