1997 960 Wagon

I checked the rear washer motor for continuity and it has none. the connector has voltage when the switch is pressed so I need a new motor. My question is since this has been non-functioning since I bought the car 3 years ago. I honestly did not think it came so equipped, until I removed the air box today for a bad airbox thermostat and saw the extra motor. I read about some check valves that can go bad.
1. Does anyone know if they are three way or two way?
2. Also is that an overflow hose that is at the base of the filler neck? It just loops and would empty on the chassis.

I did not replace the airbox thermostat it had failed. I kept the fresh air door open and removed the flex metal tubing.
3.Is the heat emptying into the engine compartment something to address?
I wouldn't think it to be that big a factor, but I have been wrong before.

Any help would be appreciated.
Thanks in advance.

 

The valve is just a simple diaphram valve it holds pressure from returning back to the bottle. It should just be a 1 line in and 1 line out.

Yes they is an overflow hose.

You can just screw the flap open for cold air in the air box.