JiffyNo5

All -

Have any of you 100CS owners fixed air conditioner problems on your own?

I had mine "recharged" - worked for about half a day, then back to blasting hot air.

There's most definitely some sort of leak. I doubt that it's worth it to pay for a complete A/C overhaul on this car, especially since I've got 213,000 miles on it (but I love it).

Has anyone here had any experience fixing leaks, or know of a good Audi mechanic in the Boston area?

Any information much appreciated!

- JiffyNo5

Mike Atkisson

I had a 94 90CS that did something similar. I took it to an A/C shop and they told me the compressor and condenser were bad. I found some used pieces and installed them.

Then I took the car to a very inexpensive A/C guy and he vacuumed down the system and recharged it. By the time I picked up the car that evening, there was no A/C.

I ended up having to replace the evaporator that is under the dash. Big pain was removing the dash and complete air box. I did a quick flush of the lines with stuff from a local parts store. Replaced the drier and orifice tube while I had everything apart. I used a cheap Harbor Freight A/C vacuum thing you hook to an air compressor and let it run for 15 mins. I then went ahead and charged the system myself and it has been working good since.

Obviously the 100 is a lot different, but it is possible to DIY the A/C system for pretty cheap.

upallnight

Since you have a pre 93 Audi, chances are that the refrigerant is R12 and not R134a, not unless a PO had it converted to R134a.. Unless you are certified to handle R12 you will not be able to obtain it legally. I'm surprise the shop didn't locate the leak before filling it with refrigerant. By law, shops are not allowed to "Top off" a system, but must locate and repair all leaks.

Ben2

You can get R12 on ebay, but it's on the expensive side.

Get a UV dye injector kit with the blacklight, goggles, die injector, etc (like $50-75), and recharge it, then inject the dye. Drive the car and run the AC until it goes hot again and use leak detector to find the leak. Fix it, recharge again, and you should be good to go.

upallnight

If the system is empty, it is not a simple job of topping it off and injecting dye and using a blacklight to determine the locations of the leak(s). You will need to evacuate the system prior to adding the refrigerant and dye. Adding just refrigerant to a system that is leaking will only cause you more problem because the system will not be operating as designed. Air with water vapor will be in the system and if the system does function it will cease to function because the water vapor in the system will freeze. Mixing water with the refrigerant will produce a by product aka hydrocholric Acid. The acid will break down the oil with in the system and eventually the compressor will suffer what is known as the black plague of death.

I would have a shop determine what is leaking and if you are capable of DIY replace the component that is leaking and bring it back to the shop to have it recharge with refrigerant.

I brought a BMW 525i Touring about 6 years ago really cheap because the cost to repair the ac system would have cost more than what the car was worth. Replaced the condenser coil, the drier, and evacuate and recharged with R134 the system. The system was cold enough to "Hang Meat" in front of the vents. The ac system was still working when I sold the car after I brought my A6 Avant Quattro.

klone121

When you lose start losing refrigerant the a/c compressor will start cycling quickly, after it gets to a certain point it will no cycle at all do to the low side cut off switch telling it not to turn on to prevent compressor failure. This switch can be bypassed by jumping the terminals with a paper clip. First check for leaks in all the lines, condensor, and compressor. R134 contains u.v. dye and will show up easier with a u.v. light and goggles. 90% of the a/c problems I see are due to a leak. If no leak is found (very doubtful) then check for operation of compressor by jumping switch.