I noticed the other day that the pilot side vent blows cold-ish, but the right side was blowing ambient, which initially made no sense to me. The gaspers in the PA46 are solely fed by the recirc blowers...they cannot provide heat.

Then I looked at the system schematic and it appears each blower (right and left) has it's own evaporator, but are both fed by a single condenser.

What would cause only one side to stop cooling?

If two evaporators they may each have their own expansion valve.

Pretty sure they do both have an expansion valve. Also, the fins tend to get obstructed by carpet fibers, pet hair, or things that fall through the back seats.

Flush the entire system out and replace the expansion valves.

The system is low on freon. Evacuate, recharge, add some fluorescent dye for future leak detection. Look for leaks with a black light and glasses.

I'm not a big fan of dye in AC systems....I think it causes issues

In my older cars there ends up being dye everywhere! I never succeeded in finding a leak with it.

Somewhere I have a very sensitive aural leak detector that you can sometimes use to find tiny leaks when it beeps or with headphones.

It is usually leaking in the hottest and nastiest place and AC is one of those systems that often benefits from "throwing parts at it". My IAR has the same AC system as the PA46 and my compressor locked up last month so once I am home this is my upcoming task.

T

How is that, Tom?

How is that, Tom?

Got it! Yes, once the system needs to be evacuated and recharged, best to do as much as possible so as to avoid opening the system again.

They really don't Michael. I'm in the European car repair business and have never had an issue with dye causing any issues. We have a lot leaks due to R134 being caustic rotting the systems from the inside.

First if it's only the right side it's a clogged expansion valve. Cleaning will probably fix it, but you'd probably want to know why it became clogged.

As for using die... I've seen the die make a mess of 58P Baron interior.

The big PA-46 shops typically use Nitrogen and 50/50 Dawn dish soap and water. The leaks are usually a fitting or near a fitting. This process can find extremely slow leaks too. The common leak place is the battery box area as that hose has some stress on it at the firewall and the flexible line that runs the under the length of the fuselage floor. It has an odd fitting near the pilot's feet.

If it's a hard line those will be a pain to find and the only way is the divide and conquer. Cap off sections and pressurize it. If it's in the condenser have fun. I'm convinced that's the first part that the PA-46 airframe is built around.

Also, if it's a rotten hard line then you have to question what was put in the plane (instead of R-12 for a Malibu) that caused the corrosion. That can become an expensive fix.

My AC was a winter project my first year of ownership. After the first couple bad hoses, I ended up replacing all the flexible lines and one male fitting at the pressure vessel, which I'm convinced was dropped and damaged when the plane was built.