A car windshield washer obtained from the junkyard can be used to make a 12 Volt bilge pump.
First, check to make sure the motor is functioning by connecting the motor leads to a car battery. You may be able to do this at the junkyard. If it runs, but screams and squeals, remove the motor from the housing, and put a small amount of silicone grease (as used in auto ignition distributors) on the motor shaft ends and the rubber seal that keeps water out of the motor. Replacement motors are available for around $5-$6 from auto stores. I would use the silicone grease on the rubber seal on a new motor as well.
Red in the drawing above shows where to cut the washer housing. Make sure you don't cut into the motor compartment. Leave some of the plastic around the motor area for mounting purposes, and leave the outlet nipple intact so you can attach a hose to it.
Silicone sealant (not caulk) can be used to seal the motor from water on the connection end. Clean the area to be sealed first with alcohol.
