Any body use freeze 12?

HEH HEH HEH!
I've still got 20 or so 12 oz cans of {gasp} the dreaded, ozone killing R-12 left! No retro fit for my Mustangs!

I don't think it is that big of a deal to retro your Fox car to R-134. Certainly not $600 worth. Get a fitting kit, new drier/accumulator and pressure switch, then have your A/C guy flush the R-12 out. Recharge with R134 and you should be good to go! I'm assuming the rest of your system is in good shape. I just bought 2 30lb cylinders of R-134 for my shop and it is down in price from last year so that shouldn't tear you up too bad.
Stay away from the R-12 replacements! I have heard nothing good about them.

I have a 10 gal canister full of R-12 can you say mad cash on the black market??? Like was stated above, shouldn't cost $600 to retro fit.

R134a Air Conditioner Conversion


R134a = $7-$10 a can – takes 2 - 2 ½ cans.

R134a compatible oil = $5-$7 for an 8 oz bottle – better get 2 bottles.

Gauge set for recharging = $20-$120 – check out the pawn shops for a bargain before you pay retail.

Vacuum pump – I use an old refrigerator compressor = $5- $20 at used appliance stores, or go to the Dump and get one for free. Be sure to have some R12 compatible oil handy to keep it lubed up properly.

Pump to force cleaning fluid through the system $20-$50 (may use compressed air to do the same thing).

O ring seal kit = $8.

R134a charging adapter = $13 ( I cut mine up to use it with the R12 gauge set that I have had for a long time).

Plastic tools to disconnect refrigerant lines - 1/2" & 5/8" = $4 each.

Flushing agent - Discount Auto Parts has some flushing solvent in a 1 gallon plastic bottle - try that first. Or use Mineral spirits = $4 a gallon, tetrachloroethylene =$5-$10 a gallon, takes 2 gallons of either one.

Miscellaneous hoses and fittings to adapt the flushing pump to the system, and the R134a adapter to the R12 gauge set = $15.

I did a R134a conversion on my 89GT, and used all stock parts. You will need to replace the dryer/receiver (about $75 if you get the one with the hose made as part of the unit), and should replace all of the rubber "O" ring seals as well. You will need to drain all of the oil out of the compressor and replace it with new R134a compatible oil.

Keep in mind that to fulfill the requirements of the EPA, you are required by law to recover any refrigerant that still remains in the system. How (or wither or not) you accomplish this is up to you. Connect the charging gauge hoses to the service ports on the A/C (red gauge = high pressure, blue gauge = low pressure) and open the valves on the gauges to dump the remaining refrigerant (if any) into your "freon recovery system", whatever it may be. Disconnect the charging gauges since you are finished with them until you are ready to fill the system with R134a. Next comes the nasty part – in order to get all the old oil out of the system, you will need to flush it with special flushing solvent, or mineral spirits (ok) or tetrachloroethylene (better, but may be hard to get). If you leave the old oil in place it will congeal and reduce the heat transfer in the condenser and evaporator (read that it won’t cool good) and possibly damage the compressor.

Disconnect the compressor and remove it from its mount to flush it with cleaning solvent. Pour about a cup of solvent into the suction port and turn the compressor center hub about 10 turns while shaking the compressor to move the solvent around inside the compressor sump. Drain the flushing solvent out and continue to turn the center hub by hand to force out any remaining solvent. Then fill it with oil: add about 6-8 oz of the new oil to the compressor large suction fitting. Turn the compressor center hub about 20 turns as you turn the compressor face up and face down to distribute the new oil inside the compressor. Catch and replace any oil that comes out of the compressor.

Connect the pump (I had an electric sump pump I bought for $20) to the hose from the high-pressure side of the compressor. Alternately, you could use compressed air to force the cleaning fluid through the system. I didn’t like to do this since compressed air has lots of moisture in it, which is death to A/C systems. Pump the cleaning fluid through the system and let it come out the hose that was attached to the old dryer/receiver. I used 2 gallons of mineral spirits and pumped it all through the condenser and evaporator. The expansion valve is located near the firewall in the high-pressure line of the evaporator, and may cause the cleaning fluid to trickle through the lines at a very slow pace. You may want to pump cleaning fluid through the evaporator and condenser separately to speed up the process.

Next comes the changing of all the old "O" rings so that the chances for leaks is minimized. Use the plastic connector tools to separate the lines, place the extended collar part of the tool so that it faces the large part of the connector and push inwards: this expands the spring so that you can pull the tube apart. You may need a helper to push on the tool while you pull on the tubes to separate them. Install the new "O" rings: be sure to coat them with new oil when you put them in. Install the new dryer/receiver, R134a service port adapter, compressor, add about more 4oz of oil to high pressure line and tighten up all the lines. Close the hood, start the engine, let everything get warm under the hood, but don’t add the R134a or turn the A/C on. Connect the charging gauge hoses to the service ports on the A/C (red gauge = high pressure, blue gauge = low pressure) and open both valves, then connect the center hose to the vacuum pump. The purpose of this exercise is to heat up the system so that when you vacuum it all down (yes, you will need a vacuum pump- mine is an old refrigerator compressor), that all the air, vapor and moisture from the cleaning fluid vaporizes and is removed from the system. Vacuum it down for about 30 minutes, this should give you about 28" of vacuum or more inside the A/C system. I have a vacuum gauge "T" connected into the vacuum pump line so that I can accurately watch the vacuuming process. This is a good time to take a soda and sandwich break since it doesn’t go faster if you watch it.

Install the R134a service fittings on the system: the red goes on thehigh side and the blue on the low side. This will help others identify that a R134a conversion has been done on the system.

Remove the electrical connector from the dryer/receiver and jumper the two connections inside the wiring harness side of the connector together: this allows the compressor to engage in spite of low pressure/no gas in the system. Close both charging gauge valves, and then disconnect the center hose of the charging gauges from the vacuum pump and connect it to the R134a can tapper. Put the R134a can in the can tapper and screw it down with the can tapper valve closed, then open the valve. Loosen the hose at the center connection of the charging gauge set until the R134a squirts out: this purges the line of air and moisture. The refrigerant is added through the low pressure side of the system, so open the low pressure gauge valve to add the R134a. Start the car and take note of the idle speed, then set the idle speed up to about 1200-1500 rpm, and turn the A/C on inside and set the fan speed on high. Watch for the pressure on the low side to drop off as you are filling, and the R134a can will get warm and stay warm. This tells you the current can is empty and needs to be changed for a fresh one. Before you disconnect the can, be sure to close the valve on the R134a can tapper.

Watch the high side pressure on the charging gages and regulate the adding of gas to keep the high side pressure under 350 psi. You will probably need a fan in front of the car to keep the readings below 350 psi. I had to put the R134a can in hot water while I was charging the system with it, or else the can got so cold that it quit flowing. Use caution when you do this so that you don’t get water in the charging adapter when you change the cans. When you have added the 2 cans of gas, the high side will read about 250-300 psi and low side about 28-38 psi. Turn the idle speed back to where it was, turn the A/C off, disconnect the charging gauges, and re-install all the caps on the service ports. Remove the jumper from the low pressure switch harness and plug it back on the switch connectors. Then put the R134a Service Sticker on, secure all the loose wiring on the system and you are done. I hope it cools good, mine doesn’t get quite as cold as it used to driving around town.

The above technical note is for informational purposes only, and the end user is responsible for any damages or injury. The end user bears all responsibility for proper recovery/disposal of any R12 refrigerant.

I have an EPA 609 MVAC certification. And yes, you can shortcut the process, but there are negative factors if you do. Sooner or later, something will cease to function like it should. Shoddy work is a time bomb ticking away, waiting to explode.

Wow, Jrichker, you think this is all worth it for a guy just doing one conversion??? Building vacuum pumps and stuff? Shops don't charge that much to vacuum and recharge, so I think for most it would be best to simply recover the R12 to the atmosphere and then replace the parts you need and then have a shop filll it up.

I work in a shop and we have done the conversions. Pretty simple really. Suck out the old R12, put the system under vacuum for about 30minutes, use the adapter kits, add the oil, then the R134A and it's all good. The R134A takes higher pressures to cool effectivly, but it will work. It is best to replace the dryer, because it gets filled with crap anyways and it's best to get all the old oil out.

Now if you really wanted to do it right, it would require every bit of the system replaced, which would not only be expensive, but time consuming. That Freeze 12 got pulled off the market, didn't it???

Why is everyone talking only about R12 and R134A? He asked about freeze 12. Freeze 12 is not a very good long term replacement for R12, it contains a mixture of heavier and lighter compounds and the lighter ones tend to leak out quickly and cause the refridegerant to become unusable. I have heard that freeze 12 also contains propain which would be dangerous.

I converted my car to 134a and it was pretty easy. I just changed the O-rings, the reciever/dryer, put in compatable pag oil, and had a couple new lines made because my old lines wouldn't work with the compressor from the 88 mustang. I think I spent a total of around $200 or $250. Not too bad and the A/C gets down to around 39 degrees at its coldest.

90mustangGT said:

Wow, Jrichker, you think this is all worth it for a guy just doing one conversion??? Building vacuum pumps and stuff? Shops don't charge that much to vacuum and recharge, so I think for most it would be best to simply recover the R12 to the atmosphere and then replace the parts you need and then have a shop filll it up.

Now if you really wanted to do it right, it would require every bit of the system replaced, which would not only be expensive, but time consuming. That Freeze 12 got pulled off the market, didn't it???

Click to expand...

I have been fixing auto air conditioning on my own cars since the late 60's. The investment in tools has paid off many times over. The last A/C tool I got was a new vacuum pump that didn't cost me anything but the time to pull it from an old refrigerator.

Freeze 12, like many other subistutes for R12 Freon, requires a EPA 609 MVAC to purchase it in the USA. I don't know about Canada, the requirements may be different. Freeze 12 is still around, although the warnings posted about it deserve some consideration. See http://www.technicalchemical.com/products-freeze12.htm for more information.