951 Windshield Washer Question

[thom4782]

Hi all:

I have an '87 951. The problem is the washer fluid seems to drain back through the lines into the tank after spraying the windshield. I have replaced both check valves near the nozzles as well as the check valve in the tank. After which, the fluid still seems to drain back.

My question is this. My tank has two lines passing through the cap into the tank. The parts diagram - see attached - shows only one line. My assumption is the tank check value goes at the end of the line that goes to the input side of the pump. Would you agree?

If you agree, then what could be allowing the fluid to drain back. All check valves work and there doesn't seem to be leak in the lines.

Is it possible both lines in the tank should have check valves?

Thanks

[djnolan]

Do the lines have clamps at each fitting? Is the line new or original? Could be the line is leaking air at a fitting due to hardening and old age.

PS: I gave up on washer many years ago, it is the only thing that doesn't work on either of my 944's.

[thom4782]

It's hard to know their age. I bought the car 15 months ago. The lines from the tank to the nozzles look like they are in excellent condition. All are soft and flexible. All fittings are clamped except those near the tank cap and at the pump. Since the fittings have ridges to hold the hoses in place, I had assumed they were air and water tight.

If I did decide to replace the hose, anyone know their actual size. Generic lines are 0.267" OD and 0.1689" ID