Freeze12 AC question on 85 280SL Euro

[desert]

My 85 280SL Euro AC was converted to Freeze12 a few years back ( I had sold the car to a guy whose wife didn't like it so I bought it back after a year) I don't know why he converted it to Freeze12 and not R134 but he did. Freeze12 is 80% R-134 and 20% HCFC-142b. Shops don't want to evacuate the Freeze12 because they say it may damage their evacuator. My question is: can I or my shop add R-134 or possibly R-12 to the system to top it off? The only shop here that uses Freeze12 is very expensive and always booked so I would like the option to top off with R-134 orR-12 if possible without screwing up my system.Thanks....Desert

[C Sean Watts]

Originally Posted by desert

My 85 280SL Euro AC was converted to Freeze12 a few years back ( I had sold the car to a guy whose wife didn't like it so I bought it back after a year) I don't know why he converted it to Freeze12 and not R134 but he did. Freeze12 is 80% R-134 and 20% HCFC-142b. Shops don't want to evacuate the Freeze12 because they say it may damage their evacuator. My question is: can I or my shop add R-134 or possibly R-12 to the system to top it off? The only shop here that uses Freeze12 is very expensive and always booked so I would like the option to top off with R-134 orR-12 if possible without screwing up my system.Thanks....Desert

Measure your pressure FIRST before adding anything. Also any R 12 system using R 134a or mix of it, should be filled with ~20% LESS than the R 12 indicated. Any mix of R 134 in an R 12 system will lower system efficiency - specific heat, heat capacity, etc...SO, don't overfill it.

If you read the 'diesel discussion' many of us there are EPA certified to use R 12 (myself included) and the test is open book. Either way - LOTS of good A/C info there...

[TOPGUN]

If any R-12 is added, the system will soon be ruined. Nothing that I know can be mixed with R-12.

[alabbasi]

legally, you cannot mix any two gasses. Furthermore FR-12 is a blend of R134 and some other gasses that help carry the R12 oil. Because it's a blend, it will leak at different rates and therefore it should fully evacuated and recharged so that the correct ratio of the blend is maintained, else it could damage your system.

[desert]

Thanks for the info it gives me something to think about before I do anything but it will not be R-12 mixed with R-134.....Desert

[C Sean Watts]

Originally Posted by TOPGUN

If any R-12 is added, the system will soon be ruined. Nothing that I know can be mixed with R-12.

If you mix R 12 and R 134a - in the right conditions - phosgene gas is the result. The same kind phosgene that was used in WWI. A leak of incorrectly mixed gases from the evaporator could result in a rapid death.

The R12 system in the car, as was installed at the factory, when correctly converted CAN safely and legally be filled with other alternative refrigerants.