mikeceli

iTrader: (2)

Hello!

1989 Camaro IROC Z Convertible..305 TPI LB9 / AT

Previous owner had it converted to R134A, but it was too low on refrigerant to engage the clutch and cool. I hooked up my R134A Manifold and attempted to charge it with R134A. As I recall, the High and Low side had about equal PSI. I evacuated the system and it passed a vacuum test.

I flushed the evaporator, using an AC solvent flushing device. After draining the Pag oil, I added the correct amount of R12 Mineral Oil and AC DYE and installed a NEW R4 Compressor, Dryer and Condenser. I let the compressor sit clutch down, on my work bench, as directed, for about 15 minutes. I then rotated the compressor approx. 20 turns, using an AC spanner wrench, as per the instructions. I removed the R134A adapters from the high and low charge ports, installed Schrader valve as needed and hooked up my R12 manifold. I evacuated the system, but it will NOT hold vacuum(leaks down in Approx. 5 minutes).

I pressurized the system to about 40PSI with dry shop and and checked for a leak with soapy water. No leak found.

I then Smoke Tested the system for leaks with no leak found.

Now what? Add a can or R12? OR R134A for testing only?

Help, please. I have NOS(New Old Stock) R12

Thanks, Mike Celi

ACebell

I wouldn't add R134A back to the system after all that work. Change the Schrader valve again (I have seen faulty o-rings on them). No mention of the AC hoses. Are these the original? maybe a hairline fracture in the hardline set?

mikeceli

iTrader: (2)

Since I can not locate (so far) the leak, I was thinking dump a can of R134A in , to then look for the dye or use my electronic leak detector. Then pull it out. My R12 is limited and about $35 a can, VS $ 10 R134A. I will try 2 new, Schrader valves, also.

No VISIBLE sign of leakage, at the original hose assembly or new parts. This IROC does NOT want to leave my shop!

Thanks!

AlkyIROC

Many places for leaks to occur but shop air is too low a pressure to check for leaks and is full of contaminates. Nitrogen at 300 PSI is the preferred method to check for AC leaks.

Common places for leaks.
Schrader valves
AC hoses or around the metal crimps on the hoses.
Evaporator inside the heater box
Compressor or compressor shaft seals.
Hose seals

I've also see the accumulator get corroded enough behind metal brackets to start leaking.

mikeceli

iTrader: (2)

"AlkyIROC" Thanks. It turned out to be a leak in my40+ year old, R12 Manifold Set. All charged up now and blowing COLD!