luvmy82

I need some help with trying to solve the mystery as to why my AC will not hold a charge on my 82 CE.

Here's some history of what has been done:

1) AC system has been completely and correctly converted to R134a. Previous owner did this.
2) When I purchased the car last year it was in February and did not need the AC until summer, and this is when I discovered it did not work. So, I took it into the shop and they did the following: recharged the coolant and found that the water control valve was not closing completely. They readjusted the valve.
3) They also checked any leaks with dye and black light and no coolant leaks were found. Chemical sealer was added for phantom leaks that couldn't be detected just incase.
4) Then, in June of last year I had to take it back AGAIN! Just blowing air. This time, they found that the heater control valve did not have any vac to it. Found out that the switch behind the glove box on the blend door was not moving enough to allow vac for the contol valve. It was adjusted and moved to control the vac. At this time, AC operated and temp was 47 degrees for the rest of the season last year.

Well, here it is spring again and checked for AC and ZIP, nada, nothing. Just blowing air.

Why can't the AC hold a charge? All the refrigerant is gone. Again.

Do I just go out and purchase an R134a charge kit and zap the AC when it's not working? Where in the hell is the coolant discharging from?

Who can help me out here?

BSeery

134 leaks out a lot easier than the good ol' R-12.

If there is a leak, a COMPETENT shop doing a vacuum test for at least 1/2 hour (1 hour prefered) should find out if there is a leak.

We had a car that kept blowing off R-12. The problem was the radiator ??!!??
The radiator was plugged, would not cool the engine and radiator enough. This caused the condensor to be overly warm, and degrade the performance of the entire system. Then the A/C would be over pressure high and bleed off.

I am betting on a leak if it works all summer and then dies. Check the o-rings.

Also, you should run the A/C at least once a month, even in winter, for at least 15 minutes. Once a week is better.

flynhi

I have been told that hoses for R-12 will leak thru the hose itself if used with R-134. I think you are supposed to change hoses when converting.


[Modified by flynhi, 3:26 PM 4/23/2003]

A C

Hard to say where it is leaking from. In the commercial field HVAC field, we often put a vacuum test on for 24 hours, and use a micron guage to measure the vacuum accurately. You obviously have a leak somewhere. I only work a little bit with R-12 (dying breed), and R-134a hasn't been put in a lot of commercial comfort cooling applications, so I am not totally familiar with either refrigerant. I am not sure about the hoses, but I have heard you definitely need to change the o-rings on them when changing refrigerants. For a good initial system test, you should try 100 PSI of dry nitrogen. Then just spray the good old soap bubbles on everything that could possibly leak. Another guess would be the schroeder valves where they connect the hoses.....the rubber is prone to leaking over time. They are easily replaced.

AC

8T1-7T9 BIONIC VETTE

Have they put a sniffer in your A/C vents ...somtimes the leaks occur on the evaporator inside the plenum box....the sniffer will be able to tell if you have a leaking evaporator.... :flag :seeya Cappy

joe73vette

If you have a slow leak, you might find it by looking of feeling for an oily spot where the compressor oil got out. Joe