I am currenlty getting my girlfriends ’97 Punto 75SX ready for selling and I have noticed a leak coming from the window washer system.
Within the engine compartment there are two tubes connected together by some sort of small plastic valve. It is grey on the top, black underneath and has an arrow on it. This part appears to be the source of the leak.

The problem I have is that when it is leaking the rear washer works fine (until it drains all the water) but when I wrapped it in tape to stop the leak it also stop the rear washer from working.

Can anyone give me a clue as to what this small part is and what it does ?

Thanks in advance

It's a check valve to stop the water in the line from draining back to the tank. I haven't meddled with the ones on the Punto yet but my Saab has 3 or 4 of them and when they are about 5 years old the rubber diaphragm in them perishes and lets all the fluid run out. The Saab ones I've taken apart and made new diaphragms out of vinyl rubber, don't know about the Fiat ones but they are probably only a pound or two to replace.

Thanks for the help

Just phoned a Fiat garage who have them in stock at 87p + vat.

Almost exactly the same answer I gave to the same question on the PuntoPower forum.

bought and replaced the valve tonight.the rear washer now works fine.

Thanks to

Desmo
&
Evil (for your reply on the PuntoPower forum)