Troubleshooting A/C Issues (Page 1/1)
ledtear AUG 26, 06:51 AM
So I am not a car guy but am determined to become one through the recent 1988 Feiro I bought. I have been doing small exterior fixes but now I have no A/C. I was told by the guy who sold it to me that he thought it needed a new compressor.

1 How do I go about trouble shooting what the issue might be?

2 The Haynes manual says that the a/c system must be discharged before working on it - how do I go about that?

That's it for now...
fierofool AUG 26, 08:30 AM
Proper equipment is required to discharge the system and recover the refrigerant so that it's not released into the atmosphere. You can test for pressure in the system by removing the cap on the nipple of the silver canister on the passenger side of the front compartment. Use a tool to depress the valve stem. If there is pressure, it will be evident. AC work really shouldn't be performed by a novice. For economic purposes, you might try to find a friend or a friend of a friend that can do the work. A local shop quoted me $1400 just to replace my compressor.

A complete AC kit can be had for about $300 retail, so at $70/hr, he was going to charge me for about 14 to 15 hours labor.
RWDPLZ AUG 26, 08:54 AM
Air conditioning diagnostics starts with system pressures. On a used Fiero, determine if the system is still R-12 or converted to R-134A. As stated above, briefly press the schrader valve on the accumulator (low side) to see if there is pressure. More than likely it's empty or near empty. Using the refrigerant-specific gauge set, check pressures and compare with a pressure chart. If it's 80 degrees F outside, static pressure on the system should be about 80 on the high and low side gauges.

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1984 Fiero SE

ledtear AUG 26, 12:59 PM
Thanks - so I know it has been converted to 134. It's going in for it's initial inspection, so I think I'll just have them discharge it and then work on replacing the compressor myself. Any step-by-step instructions out there for replacing the compressor?
ledtear AUG 26, 01:34 PM
1. I am having it inspected Saturday, I am going to ask them to discharge the A/C system.

2. Replace the compressor (fill with oil but basically just in and out)

3. Take it back to vacuum test and hopefully put in new Freon. That works right?
sledcaddie AUG 26, 02:01 PM
I am a proponent of actually testing something first before replacing it. If the "inspection' involves drawing the system down, and checking for leaks, this should show if the compressor is leaking or not. A dye can be installed, and, using a black light, it will show where the leakage is located. Why replace the compressor if the issue is merely a leaking O-ring? What if you replaced the compressor ($$$$) and then the freon leaks out someplace else? The main issue for most of us, is we don't own the expensive equipment to test the system.
RWDPLZ AUG 26, 04:03 PM

quote
Originally posted by ledtear:

1. I am having it inspected Saturday, I am going to ask them to discharge the A/C system.

2. Replace the compressor (fill with oil but basically just in and out)

3. Take it back to vacuum test and hopefully put in new Freon. That works right?



At minimum replace also the orifice tube and accumulator. Put 4-6oz of the oil in the accumulator, 2oz in the compressor. Check for leaks after vacuum.