1972bluelt1

Has anyone converted a c4 AC from r12 to r134. I have an 89 L98. I was told by a mechanic that it doesn't work well, especially when the car is stopped.

thanks

Scott-89

Mine was converted already when I bought it. It doesn't get very cold but it works well enough I guess. When it's really hot I rarely drive it anyway.

1972bluelt1

same here. mine is a conv and I don't use the AC all that much.

Frizlefrak

In 2000, I converted my 84. I installed a new compressor, orifice tube, and accumulator. I replaced all O rings and vacuumed the system. I then charged with PAG oil and 80% of R12 rating with R134A. I got 42-45 degrees at the vent in 100+ ambient temps. Not bad. I had to add 2 cans in the next 10 years I had the car.

The reason some conversions don't work well is that they are usually overcharged. You don't use as much R134A as R12. Convert and never look back.

JackDidley

I did mine in 05. Just bought a kit with oil, 134 and fittings. 20 minutes later it was blowing cold. It will still freeze your *** off.

Elrick

How do you know if you overcharged it. I have an 86 and I am getting some heavy gas pedal vibration when the ac is on. It has been converted and I dumped in some more. I charged it up as directed and the can had a meter on it to see if it needed more. Just wondering if too much has caused my problem. It does cool the car well though

romankrzy

The only real way to tell if it's overcharged is with gauges or true pressure readings and it helps to read the high side too. Some times with a badly overcharged system the low pressure line will get some frost or even freeze up after running a while. Typically it should sweat at idle with the system running since the low side is the cool side and the high side is hot. We used to just charge systems on a hot day until the low side started sweating and it was really close.

Mine was converted and seems to work well. My other cars that had R12 in them I converted to Freeze12 which is more R12 "like".

I have the software and cable to read my ODB and there is actually a reading from the high side pressure which I have been using to fine tune the fill on AC since the PO did a lot of "odd" things and I am trying to get the car back to stock.

Frizlefrak

Look at the fill specs for your R12 system, and multiply by .8.

When we were young and poor, we used to use the "hand in front of the vent" method too. Fill the system just until it stopped cycling and was nice and cold and then stop. Not exactly scientific, but worked well.

Gauges are the real answer.

jhammons01

converted my leaky system in '06....I add a can every 6 months and call it a day.....cools real well

Frizlefrak

Add some dye, locate and repair the leak. Probably just a seeping O ring.

ezspdr

I just had my 1989 converted to the R134 system and I have to say it works pretty good. I bought the 89 about 6 weeks ago and was told by several people that AC system on the early C4s wasn't a great system to begin with. I live in central CA, it's been and will be mostly in the 100 degree range for about a month now with another month to go. The R134 cools the car nicely as far as I am concerned. Cost me $250 for the conversion + $125.00 to replace the condenser that was bad.

jhammons01

yeah....it's on the front of the compressor and on the "to do" list.........

KARR

My 1992 still has the r12 system, and I love it! It can freeze me right out of the car in San Antonio! I agree, that r134 does not get as cold, and that is why I won't convert over.

I talked to my mechanic, and he told me he has an r12 license and can still get some when I need it, so I'll be Chillin in San Antonio for a long time!

blown1981z28

I disagree. A 134 system can work just as well as a 12 system. My retrofitted 87 vert is cooling 35 degrees on a 75-85 degree day and 45-48 degrees on a 100 plus degree day. Some cars take to retrofitting better than others. I have found that the vettes I have retrofitted cool quite well. I wouldn't hesitate to retrofit. How well a system cools depends on the condenser and evaporator. Flush the system, change the oil, change the o-rings, change the dryer, and charge 80%. I also went with an early Ford orifice tube to get a colder charge.

shbbykins

When i first did mine it was fine. after my engine rebuild not so much. the sucker will squeal for a few seconds when you first turn it on but then will stop. if left idling for too long it will squeal. I rarely run the AC anyways but its still annoying. Theres a noticeable feeling in the way the car acts when its on. Had it stall out once or twice. Poor mans AC works fine for me.

Blue89C4

Sounds like your compressor is locking up...

shbbykins

yeah i dont feel like spending hundreds for a new one at this point in time. A TPIS AC delete will suffice and clean up the bay.

92LRC

anyone know what year GM changed all the vette ac's to 134? I need to refill my freon and I'm not sure if I have 12 or 134.

In case anybody didn't figure it put by my sig I have a 92.

Thanks

8valve

I would like to learn as I want to convert my 87 to R134a. How and why does the Ford Orfice work better. Do you have a part number ? Is it plug and play install on a C4 Climate Control System?

Thank You
8Valve

GreyGhost

Mid 1993 they changed over. I still have R-12. I just charged my system today and cold as ever again.

Im 9608, vin..see where you fall into that.