View Full Version : AC advice

10-14-2015, 12:13 PM
looking for practical advice for getting my AC going. I've had the system open for some time (over a yr) and don't want to break the bank replacing everything and I'm seeing a couple options.. plan is to change seals, vac out and one of the following.

a. I see R-12 on ebay.

b. regarding r-134 ...." After a couple of years most service shops found that just adding ester oil, replacing the accumulator, and leaving any remaining mineral oil in place provided acceptable performance, in practice".

c. I've also seen R-134 with anti-moisture/corrosive mixed in.

d. also on Ebay...12A

HC-12a, also called ES-12a, OZ-12a, and Hydrocarbon Blend B, is a "drop-in" replacement refrigerant for Freon-12 and to a lesser extent, R-134a. HC-12a is a mixture of hydrocarbons, specifically propane (R-290) and isobutane (R-600a), and is therefore considered nearly non-ozone-depleting when compared to dichlorodifluoromethane (R-12, Freon-12) or 1,1,1,2-tetrafluoroethane (R-134a). The mixture can be used in refrigeration systems designed for R-12. HC-12a provides better cooling than an R-12 system retrofitted to R-134a, with much greater energy efficiency as well. Unlike R-134a, HC-12a is completely compatible with the hoses and oils used in R-12 systems, making the conversion much easier to accomplish. HC-12a is also patent-free due to its non-synthetic nature.

Disadvantages to using the HC-12a mixture in R-12 systems is that it is potentially dangerous and is illegal in the United States. The refrigerant used is propane and other hydrocarbons which are flammable. However, it should also be noted that R-134a (and other refrigerants) are just as flammable when mixed with refrigerant oil, yet the quantity of refrigerant and oil in a typical system is so low that the danger in any case is minimal.

e. stop being a wimp and just deal with no AC.

10-14-2015, 12:42 PM
Just a note that an open system is at risk for moisture collection thru out - especially the dryer. If it's been that long, that puppy may be toast and need to be replaced. Just a reminder that even if the system is disabled, it can pay benefits later to try to close it up.

I'd go ahead and proceed with a 134a conversion. A system that is otherwise serviceable may just need to hardware kit to convert the ports. My '90 SC had been changed over before I got it. Over time i've replaced the compressor w/new clutch and also a new/narrow condenser to unshroud the IC. I made sure to not leave it open during work and vacuumed it down to confirm no leaks and to purge contaminants, etc. Works terrific.

There are threads here with details on repairs and change overs as I recall.