bucket

The AC on my 1969 corvette was modified to use R-134A instead of R-12 refrigerant by my mechanic. But the system leaks the R-134A refrigerant. Has anyone else had leaks with R-134A refrigerant in their modified classic corvette AC?

fishslayer143

Its not the R-134 that's the problem.. your mechanic likely used the wrong type O-Rings .or did not do a complete flush first. .. I converted mine 9 yrs ago.. Ice Cold and never any issue.. I also did the C4 Blower wheel conversion... a world of difference in Air Flow

Dynra Rockets

134a has a much smaller molecular weight than R12. Holes not small enough to leak R12 will leak 134a. When converting you have to make sure all seals and fittings are perfect - being able to hold a vacuum for a couple of days is a good start.

mrvette

You are correct, need the green rubber gaskets, and to change the setting on the POA valve but it's been too long now, I forget the setting.....helpful to change the pressure valve also, but the real trick is to leave the black material off the wet bulb on the discharge tube of the evap coil....A6 compressors really need updating too, which is yet another reason I went '88-91 vette serp drive with the modern compressor....

terrys6t8roadster

My compressor failed, 69 coupe. Upgraded with the Ecklers compressor, POA valve and expansion tank. Took it into a shop for testing and charging to R-134. Worked great for 2 months, then only warm air. I suspect that the coolant leaked out. Maybe this summer I'll address that issue again. T

fishslayer143

if you don t flush thoroughly and change to the green O-rings , it will fail.. the stock O-rings will deteriorate and leak. Its just that simple... and best to change the Dryer too.

IzzyRock

This is correct. Technically the flexible lines should be replaced as well. Compressor oils are not compatible either. R12 uses a mineral oil and 134 uses polyolester oil. There are other R12 replacements on the market that are direct drop in that don't require oil swaps or line replacement but not sure if they are automotive approved. One nice replacement is R414b.

Street Rat

New seals and tight fittings are key to keeping the 134A in the system. If the system is iffy that darn stuff will find it's way out. I went to the ac shop four times before I found all of the leaks. Fitting, hose, schrader valve, and another fitting. All leaking minimal amounts making them hard to locate.

After the conversion I am very happy with the cooling in the car. It's black on black and I live in Central Texas where the temperature frequently reaches the 100s.

Good luck with your project.

IzzyRock

My C3 isn't on the road quite yet but my C5 is black on black. Can't remember the last time I used my AC. But weather in central Iowa is slightly different. Haha

chevymans 77

Find the leak and fix it.

No need to take a shotgun approach, no pun intended at anyone.

Just repair the leak.

Pressure it up and spray the hoses and fittings down with soap and water then look for bubbles.

Neal

68blvert

charge it up. inject 1/2 oz- 1 oz dye. run it till it quits working again. use bright a real bright black light while wearing uv enhancing glasses. no matter where it leaks the dye will show you. the dye don't lie.lol