problem with air-con at T350c

[uli]

all the time we (...my garage) have to refill the cooling agent for the air-con, and although it is a fluorescent agent, they cannot find the real problem. If it is refilled the air-con works well, but just for some days and then its performance is decreasing while losing the cooling agent.
Is there anybody who was yet confrontated with this problem?
Any help?
Thanks a lot, Uli

[targarama]

Sorry, can't help other than to say it sounds like you have a leak in the system, but I expect you know that. How about trying an aircon specialist, or even a call to the factory to see if they can suggest the most likely weak points which may leak in the system.