My windshield washers have never squirted fluid out since I've owned my 944. After researching this, I assumed that the two check valves were the issue. I've replaced both check valves, and now I basically just get an occasional dribble out of each nozzle. Better than before but not good.
Note... before putting the driver's side back together, I checked that there was flow UPSTREAM of that L-shaped check valve. So I thought I was all set to proceed.
I also have taken a very fine needle and cleared each of the spray nozzles of any gunk.
So what should I do next? Seems to me that the pressure may not be strong enough to fully open the check valves?
Thanks for any guidance.

 

Make sure the check valve on the pickup tube is working and flowing correctly. There should be two tubes going into the reservoir from the blue cap fittings, make sure they are both there. Then make sure there are no leaks in any of the tubing and connections. Any leak can allow all the fluid to siphon back into the tank. My experience is that these pumps do not create much suction if the pump is not primed. Not enough vacuum to prime itself from a non-full tank.

 

Make sure the tank is clean and the pump is not clogged or picking up crude if you have not already done this. Move down the supply chain. Run the system before the check valves make sure it flows well. If you have a extra set of hands have someone hit the button and put you finger over the hose and just get a sense of pressure. Did it feel like it had some umph or weak. Maybe time for a new pump. Of all things it needs to be rinsed and clean from the years of build up. Tank out and washed all lines rinsed and compressed air backwards through the nozzles then both ways until they are clean.

 

it was less then $50 to just replumb the entire system. I did that and have been working fine ever since.

 

Thanks for the input.
Turns out the issue was that there was a crack in the line near the passenger side hood support. So some of the fluid was leaking out rather than squirting onto the windshield. Replaced that line and all works well. First time in 6 years that the washer system is working!