A little late for a reply, but I went through a bunch of AC repairs last year with my
L5030 and thought I'd add what I learned.
First, the condenser needs to be cleaned out. I've found that blowing it out with air on a periodic basis is good, but about once a year Ipull off the air cleaner and light assemblies and flush the condenser (& the radiator) out with water real well. When the condenser is clean, you can hang meat in the cab on even a 90F+ day. By the same token, I can tell when the condenser gets clogged up as the temps will slowly rise, indicating that the fins are once again plugging up. Depending on what I'm doing, this can happen fairly quickly.
With that said, last year I basically had the entire system shoot craps. It was working well, and then one day it went to simply blowing ambient air temps. I had a lot of loader work to do, and it was hot, so I just ran with the doors open for a day and then took it into the dealer. The verdict -- the compressor had "shelled itself out," and that took with it a variety of other parts. In terms of age, it was well out of warranty ('05 model), but I only had about 500hrs on it so the dealer really worked on Kubota to replace the parts. All in all, I ended up paying about $300 in labor out of what was, in total, about a $2K repair (compressor, alone, was over $1K).
There's no moral of the story other than to keep the compressor cleaned out. Likewise, the cab filter as that can impeded airflow through the roof if it gets too clogged. But if your AC just stops one day, all I can say is to hold onto your wallet! :0
