I live in South Carolina and bought the car in April. From day one of ownership the AC did not work. However before I even brought the car home I ordered a replacement high pressure line for the A/C as it is a common fail item. So much so that Mazda has revised the part…twice! I bought the latest revision.
Note: I did not take any pictures during this repair so my apologies for this being text heavy.
When I got the car home I went to work on it replacing the exhaust, installing the windshield trim and finally replacing this high pressure line. As it turns out, the line was not the problem and since it was still the first version of the line based on the part number, it may have been original, but it was definitely not the issue. Still, I installed the new one because I’d feel better with the revised part. Also, if I was going to do it, now would be the time as there was no refrigerant in the system. I didn’t drain it, it came with none in the system. It had leaked from somewhere.
New A/C line installed, and not completely convinced it was the issue, I used a part store R134a refill kit and charged it up. The A/C was ice cold and I was super happy. However, as I removed the connecter from the Low pressure port of the A/C system I discovered a major leak. The Schrader valve in the service port was bad, it started spewing R134a out at a rapid pace. I immediately grabbed the cap for the port and screwed it on. Leak stopped for now. At least it wasn’t spraying into the atmosphere anyway.
At this point I was happy the A/C was cold but still weary about the system in general. Knowing at some point soon I would need to get the leaky service port sorted. That point came quickly. After just three days the system was bled dry again. Now that it was empty, I took the initiative to replace the Schrader valve in the service port as well as the drier. I filled it up, was confident it wasn’t leaking now and drove it for about two weeks with ice cold A/C.
But that wasn’t the end of this story. After two weeks the A/C was warm again. At this point, reader, you may be thinking that I would be taking the car to a professional to have them diagnose and fix it. But that would be incorrect. The system still had some refrigerant, but it was very low. I noticed that when I would turn on the A/C that I would hear a split second of something spraying from the driver side of the engine. Just a very quick “pffft!”. I didn’t see any signs of leaking though so I figured the compressor was on the way out and leaking. I quickly searched eBay for a replacement and found one from a 2020 with 24k miles on it for $50. I figured even if it wasn’t leaking, I’d much rather have a compressor with 120k less miles on it, and for $50 that’s worth a try. Especially when it takes only about 30 minutes to replace.
A few days later the new, used compressor arrived and it looked to be in good shape. I added the recommended amount of PAG oil to it, I think it was 8oz but don’t remember exactly and swapped them out now that the system was bone dry again. While I was there, I also replaced every O-ring in the area using the factory O-Ring service kit from Mazda.
So now I had a “new” compressor that was tested and known to be good, new O-rings, new drier and a new Schrader valve in the service port. We should be good to go. But we were not. Three weeks later the system started to act up again but at least it no longer did the “pffft!” sound. At this point I decided to do what I should have done at first and just buy a cheap, Amazon UV light. The PAG oil I used has dye in it to detect leaks so if I had one, this light would show me where.
The first time I used it, I was horrified. The A/C compressor and surrounding area looked like a crime scene. Green dye everywhere! But then I remembered that I did spill some oil removing the old compressor and the dye I used in the new one was yellow. The oil that poured from the old compressor was green. So, I cleaned the area up and drove the car for a few days with the A/C running as best it could to try and see where the leak was.
When I brought the UV light back to the area, it was still clean. I started looking around more and turned my attention back to the previously leaky service port. There was yellow dye all over it. The new Schrader valve was not sealing properly either and the pressure was making its way out through the plastic cap. I went back to my local auto parts store and bought a whole pack of new valves. Once again, the system was empty so I swapped the valves and recharged the system. No leaks from the new valve but just to make sure I also put an O-ring inside the plastic service port cap to make sure it seals properly against the metal service port.
After two weeks the A/C was still blowing ice cold. Satisfied, I took it to a local service center to have them properly evac the DIY R134a from a can, test for leaks and recharge the system. They did not find any leaks and the A/C has been working like new for nearly two months now. I’m not sure what the final solution was, the new valve or the addition of the O-Ring to the port cap but so far so good. I periodically check for leaks now and the system has been tight and leak free, or at least I haven’t found any dye with my UV light leaking out anyway.
Supergoat Garage 