Sorry cant help on this but have a couple of suggestions;
Try a scrappies... (Spanish= Desguace)
I had a problem with my Renault Scenic washers and got a S/H Bottle and pump for just 10 euros...
Turns out however problem wasnt a weak pump but simply blocked jets...
Pull delivery pipe off the jets and see if water is pumped when you operate the washer...
Girl at local repsol garage cleared jets with an opened out paper clip...and then berated me for using water in the wash bottle.
Use proprietary washer solution, no problema...
Use agua mas sedimentario...
Hope this helps...