Headlight washer dribbling?

[M3KUK]

Hi, my drivers side Headlight wash nozzle is slowly dribbling water and emptying my washer bottle.
What's wrong with it? There are some connector/valve things in line with the washer pipes, could one of them be faulty?

Thanks Mike.

[Brianmoooore]

Duff (or previously removed) non return valve in the washer line. Should be about 6" back along the pipe from the nozzle, IIRC.
15 on here: http://2009.bmwfans.info/parts/catalog/ ... leaning-2/