Matt_Colie wrote:

Let's face the fact that the reason that HC-12 (propane and isobutane) and other non-freons are illegal in some states is because they work and they are inexpensive. In a vehicle, the fire danger is a joke. If you are involved in a accident that opens the system, all the gas will be gone in short order. OH - By the way - read about R134a, it is not only flammable but also toxic, and the combustion by-products are toxic - too.

As to legality, that is determined by state laws. The EPA thinks it can outlaw it use in most cases, but it does not have the authority to do so. All it has said so far is that it has not the data to advise that it is safe to use and even though it is not classed as a "refrigerant" (it is technically a fuel gas), they are trying to tell everybody that it has to be handled as a refrigerant by a licensed technician and cannot be dumped to air, it must be recovered. (They are hoping this is a stopped as there is no reprocessing available.)

I have been working on old refrigeration systems for years now, and I will never again convert a system to R-134a. If you cannot or do not want to bother with collecting enough R-12, then use HC-12a and never look back.

Still want to change to R-134a (that will be banned in a couple of years because of its global warning potential)? All you have to do is disassemble the entire system and flush every part clean of its original oil and refrigerant. When you are reassembling it, replace every seal and gasket with material that is compatible with R-134a. Then with the system assembled and a new dryer fit, evacuate the system to 0.1mm absolute pressure and hold that for 2 hours minimum. Maybe nobody told you that R-134a will react with moisture and form corrosive compounds. Now, recharge it to spec and you will have an operational system that is about 3/4 the capability and efficiency it used to have.

Decided to try HC-12a??
If the system has been open, replace the dryer and evacuate it to 10mm or so just to get the air out. Refill with HC-12a by the calculated weight. It is lighter than R-12, but the can count works out about the same. The sight glass is usually no help. At a high idle (~1500), the low side should be about 20PSI. Enjoy A/C like you never had before. It will be more efficient and have higher capacity. The HC stuff has no compatibility issues with anything.

Matt - the guy that ran ships too long to put up with Bu115h1t.

REBGORV wrote:

My vehicle is a 92, 38' American Eagle J, with a 8.3 Cummins diesel.
I need a recharge on my dash air, currently the original R12.
A product by Enviro-Safe called ES-12a is a hydrocarbon based replacement for R 12, completely compatible with the original gas.
It is flammable, but otherwise a perfect replacement gas.
Has anyone had experience with this or similar products ?? I'm about to try it....So, any feedback greatly appreciated !!!
Rebgorv

rgatijnet1 wrote:

As mentioned, R-12 will work better. I used it in several of my Classic cars and if the system has been checked for leaks, R-12 should last for a long long time so the cost of the R-12 itself is really insignificant.