Willie

Hi Trevor I can't see it being the cap as every time I open it there's loads of pressure behind it, underneath the reservoir you can see the staining of the water on the body, will have to check to see if garage have something like you say to blow out the air under pressure, it's a pain in the a.... cheers and thanks again

Help required Iv An A4 2005 1.9tdi, over the last number of months my heater only works whenever it wants, now am loosing the coolant out the resovour, system pressure checked for leaks, all good, new water pump, thermostat ,radiator and alternator fitted over the last months, tried bleeding air out the system, no blockages as iv ran water hose through the system via the internal heater hose back out the resovour, any advice would be much appreciated, thanks