Need a charge freon change over? is it easy?

 

Easy? Yes! but depends on who you're asking! There are many opinions on this, what I can tell you as an HVAC guy is no refrigerant cools like R-12!!!! R-12 used to be outrageously expensive but I have found it to be more affordable over the last couple of years, I will not convert any of my cars ever unless the price of R-12 goes back to $500 a pound. I have bought 12 ounce and 16 ounce cans of R-12 and I have also purchased a 25 pound tank and all for less than the price of converting. If youre going to a newer style system like vintage air that is a different story.

 

Hey man I totally agree with you I bought 2 30 pounders in the last five years one of them was eight dollars and the other one was a really cheap also at an estate sale

 

I changed a Elco years ago. The compressor went out, so while I need to buy a new one I changed over. I have to say, that I think it was not as good as R12. If everything is working, and you have R12, I would stay with it till you can't get R12.

 

A lot will depend on what is in your system already. Has it been converted to R-134?
To properly convert to R-134 you will need a new condenser of the proper type .
In addition, the entire unit must be disassembled and all units cleaned of refrigerant oil and all "O" rings and seals replaced with green "O" rings.
PAG refrigerant oil must be used and the access ports changed to the R-134 type.

As others have already mentioned, if the system is already set,up for R-12 . Then stay with that.
R-12 is available on E-Bay quite readily. Before fully charging, put enough in to pressurize the system and check for leaks with an electronic leak detector.
If the system is opened for repair , The receiver-dryer should be replaced and the system vacuumed before charging.

 

I worked in automotive A/C in Phoenix during the '90s and it is true that r-134 will never cool the way r-12 did. But it can get close. There are two different schools of conversion though so beware!

The cheap way to convert is to pump out the r-12, pour out the old compressor oil and put in the new, add the screw-on port adaptors, gas it up and send it out the door. This will almost guarantee a failure later on

The right way to do it is to disconnect every line and connector, change the rubber (black) o-rings to the newer silicone (green) ones and run a cleaning agent through the entire system. Replace the receiver/dryer and any weak components, have the POA valve adjusted or change to an expansion valve, replace the compressor or have the original cleaned and re-sealed, add the new oil, vacuum and re-charge. It will work well if your cooling system is in good condition, but never as well as it did with r-12. The need to replace the serpentine condenser with a newer parallel flow one is debatable, but it will help. Any modification that will assist with removing heat from the refrigerant is a good thing. YMMV!

 

In addition to the above, I was informed by a local AC shop that R-134A operates at a higher pressure than R-12, so in a hot environment (like Arizona) the high side pressure can get VERY high and blow out the front compressor seal. It was recommended to install an auxiliary electric cooling fan in front of the condenser to help keep the pressure within reasonable levels and prevent front seal blowout. The shop's recommendation was to use R-12 until it was no longer available.

 

Once, when things went really wrong on an install, I saw pressures over 500 psi! Fortunately noting was damaged and the problem was corrected, the spike was only momentary. I also experienced a dryer explosion right next to my head. I was very lucky on that one.

 

On avg, how many R12 12 oz cans do you need to recharge an A/C system once they are not blowing cold any longer?

 

If I remember correctly, on cars with sight glasses in the dryer you were suppose to add refrigerant until you didn’t see bubbles in the system, then add a 1/2 pound more. That’s assuming the systems was somewhat functional and wasn’t contaminated with moisture or other debris.

The total system capacity is vehicle dependent. And the older A/C systems hold much more refrigerants than today’s systems, regardless of vehicle size. I think most 2 door A body cars held 4 pounds of R12, my neighbors Suburban with rear A/C holds 3.

 

If an ac system was already converted to R134, can you return to a R12 system?

 

If you system is still R-12 and just needs a leak fixed and charged, stay with R 12. Far less money that to convert. R-12 is coming down in price because there is nearly no demand for it. You can find R-12 for less than many newer refrigerants. Our 404A cost went up 400% over the past 6 months and is now WAY more money than R-12. Not that you can use 404A in your system but just comparing.

 

I need to start shopping at these places!