I had a
problem where no screen wash was coming out of the back wiper.
When I took the plastic trim out the boot, the hose had popped of from the wiper motor, but when I connected it back, it was leaking out the motor unit into the boot.
Had to buy a new wiper motor which fixed the
problem. Don't know what caused it, but it happened after all this freezing cold weather we've had recently, so maybe it froze, expanded, and bust, but who knows.
There is a tiny nozel that slides into the wiper spindle to direct the water onto the screen, so if anybody has low pressure problems, you could perhap try replacing that, part no. 3b9955985a.