Hi all , I'm wondering if you may be able to help me with a query . I recently got my s3 back on the road and had a few days trouble free motoring then all of a sudden I've started hitting problems , I'm presuming it is the dump valve which is a turbo dynamics one with AMD on it , im guessing its the right type of dump valve as it came on the car so I have stripped and greased it but for the life of me I can find the pipe that goes in the top , I believe it may be the vacuum pipe ? The original vac pipe seems to be plumbed into a samco hose at the rear right of the engine bay . Is this top hose the vac hose that activates the valve or is it the pressure from underneath that pushes the valve open , the hose before for the valve has popped off once or twice . Any help would be greatly appreciated .