kevmey wrote:
I'm having similar problems on my 84 944, in fact the windscreen washer system has been the bane of my life since owning the car!
Did you replace the non return valve at the foot of the pick up tube, or put another non return valve further up the pipe work?
I've been sorely tempted to rip the whole thing out and put in a manual pump system!
What seems to be the issue with your washer system? When I was recommissioning my system, I disconnected the output hose from the pump and blew some air through with my bicycle pump, this cleared any grime that had clogged up the system over the years.
There should be 2 NRV's fitted further up the system close to the washer jets, first in line is a T-Piece NRV, second is a 90deg NRV, both are still available from Porsche(as of early 2018 when I bought them):
914 628 433 00 NRV T-Piece £6.98
477 955 481 NRV Right Angle £6.68
Additionally, braided look hose and the intank filter/NRV are available from Porsche.