after nearly 2 months of trying 5 days ago I finally seem to have solved my air con problems, with to my mind, costly lessons learned.Firstly there seems to be a large part of the motor industry appears to think invest in regassing equipment have motorists come along regass their systems, then when there is some sort of fault, reclaim back the gas(its a legal requirement they do so)and still charge.I just could not get a reasonable diagnosis of what was wrong. In fact the 1st time I had it regassed when I got into the driving seat the car interior was bitterly cold Next day it simply wouldn't work, when I returned to ask what could be wrong. It could be this- It could be that, and when I wouldn't leave miggy to their tender mercy, they degassed the system telling me to return when I had had the system put right. I then went to a garage advertising to be an air con specialist.They allegedly regassed the system and reported a blockage somewhere in the system. Again no definite diagnosis or quote, finished up as another degass.By now desperation had set in and I remembered a few years back I rebuilt an insurance write off 16v ecotec Cav for myself with bad frontal damage And a firm called Sewells of Leeds rebuilt the air con system with great success.Sewells are true tec experts doing all aspects of motors inc buses and HGV tachographs so I thought it might cost me an arm and a leg but my problem had a good chance of being sorted. I asked them 1st to diagnose what the problem was, a couple of hours later they told me the gas inlet system valve was faulty and recommended the valve and pipe that carried it be replaced at a cost of £120.00,So I agreed got a price, paid their invoice in full, and then oh dear should have known had to wait a further month for the part to come from Germany,To digress, a few months back I ordered this super HP laptop I'm useing direct as I remember from Mephis USA,2 days later I was takeing delivery at my front door,and what's more was able to track it's progress.The conclusion Ive come to is if possible make the person or firm responsible for putting the system 100% right,and as is the form with most other jobs give a quote for doing so.This way you may be able to diy it (after 1st getting it degassed with an under takeing to regas)Of course I'm now makeing it my business to get to know as much as I can about the science of air con in cars. I am amazed that so little is known especially on the Forum.Well as promised in a previous post, there is my experience of present air con in cars.Hope it helps others avoid my mistakes when remedial action is required. Another thing may help I've been told that a lot of problems can be avoided by working the air con for a short period once a month every month,even in winter months.