When I fill up the cleaning fluid tank for the windshield and headlight washers in my M6, the jets for the headlight washers start to leak the fluid until a level very close to the warning light sets in in the check control. The car has got two systems, one for intensive cleaner (which I do not use)and the windshield/headlight washer jets. What the heck is wrong, leaking tubes that admits air to the system, one way valves (if any) stuck or what, any advice or tips from experience would be useful.