A/C Issues - Losing gas
 

Hi Guys,

I have to turn to you once again. Since I purchased the car in Winter I did not use the A/C on cool, however when the heat kicked in I noticed that the A/C is not cooling! It blows only 'air'. I took the car to an A/C workshop and he told me refrigerant was very low. He filled it up and I was good to go for 2-3 weeks, after which the same symptoms occurred. Took it back, filled it with gas again, and added some sort of yellow dye that glows in the dark to be able to identify the spot of the leak. Another 2 weeks pass and I am low on A/C gas once again. We spent a few hours in the evening trying to pinpoint the location of the leak to no avail. He even tried pressurizing the system with Nitrogen and it seems to hold well (1-2 hrs).

Any ideas how this refrigerant is being lost or from where? When I have the A/C on and the fan on low, I constantly hear a noise as if the refrigerant is constantly moving.

What was the result of the yellow dye job? Seems like the entire point of using that is that without it finding the leak is a needle / haystack proposition. At least you know the compressor is good when it has freon, that's a huge plus. All I remember from AC school for cars (I was 16) is a high pressure and low pressure side, make sure you get that right if you intend on screwing with it yourself otherwise bad juju can take place.

Yeah, there is absolutely no way to find such a slow leak, other than dye. Once the dye and refrigerant have run their course, every single millimeter of tubing must be inspected closely, along with the compressor, condenser coil, and evaporator coil. No short cuts here.

90% of the time, the leak is at a joint between tubing or at the compressor. Also pay special attention to any tubing that is in direct contact with anything else. Vibrations in the car or system can make the tubing vibrate against anything it touches, wearing a pinhole through it.

Checking every inch (and especially all of the connections) in an A/C system is the only way to find a slow leak. Its almost as painful as trying to find a short in a wire harness. You're on the right path, just be persistent.