Hi all just been to Stockport Mercedes dealership about my air con not working, it has been gassed a while ago but that goes within a week so I know there is a problem, they told me that in order to find the problem they would gas the system up with nitrogen and use a sniffer is this something new as I thought they used a dye, the problem I'm having is they said they would have to drop the front bumper (not sure if that's needed) in order to do a proper check this would only cost about £500 plus another £500 for the condenser if its needed, does any one know of a good place to take my car around the south Manchester area also does anyone have an idea of the costs involved? and do you need to remove the bumper to replace the condenser any help and comments will be much appreciated.