thanks donkin for the technical info.
you are right about the compressor short cycle, thats what happend before it stopped.
i now know for sure that the condensor is leaking, from the lower off side mounting bracket.my guess is that the welding has corroded where it joins the condensor. it must be such a tiny hole, cannot hear any gas escaping, just find a tea spoon size of fluid.
i reckon that the fluid must 'lay' in the bottom and is pushed out untill the pressure is not strong enough, hence why i had 1.7 bar left.
the garage had recharged the car before i bought it, they knew it was not working & probably thought that it just needed a recharge.
surly the gas does go and should be recharged once every 2-3 years ?