Rear wash wipe

I have a '98 A6 Avant and I've had a problem with my rear wash wipe for some time, where the wiper would stutter across the rear screen, stopping and starting whenever it wanted.
On top of that, some time ago the washer stopped working. You can hear the pump running but nothing gets to the screen.

Last week it decided that it wasn't going to turn off and just stuttered across the screen regardless of where the wiper stalk was positioned and didn't stop until we stopped the car and turned off the ignition.

Yesterday my husband fitted a complete new wiper motor unit with washer jets etc and yippee, no more stuttering, just perfect clean sweeps http://www.audi-sport.net/vb/images/smilies/rock.gif

The bad news is, still no water http://www.audi-sport.net/vb/images/smilies/sos.gif

We had assumed that the old one had become blocked as part of it's general failure due to age, but the unit I've fitted is brand new, so surely it can't be due to blockage. If we disconnect the pipe and operate the stalk, water is flowing through the pipe, but when connected it again - nothing.
You can see the pipe moving from the pressure, but does the pressure need to be a certain amount before forcing it's way through the new unit.

Will a new washer pump solve the problem.

Any help very much appreciated.

TIA

It is common for this pipe to come loose at a few possible areas which would reduce the pressure and is worth checking. There are push joints found on the passanger side running down the lower kick panel, also a joint where the pipe runs over the rear wheel arch, in near the rear seat bench, not sure on its exact position. When freezing the water can freeze and expand pushing these joints appart, check the area mentioned and also in where the pipe goes From the car body to the tailgate, in the rubber cable sleeve, the opening action could cause the pipe to kink or be burst.

Andy

The washer pipe on my A6 always used to pop open at the rear,If you look for the pipe at the rear there a stupid design of a pipe ie; 2 90degree bends joined together just put a piece of pipe between the 2 and that will be the rear one sorted.