Will this pump connect to my existing washer hose and reservoir?

Yes. This pump is designed for direct retrofit at the factory reservoir location. Your existing hose and nozzle lines connect without adapter fittings.

Do I need to drain my old washer fluid before swapping the pump?

It's a good idea. Drain the reservoir, unplug the old pump connector, unbolt the pump, then drop the new one in and reconnect. Clears out any debris that may have collected inside.

What if the pump doesn't spray after install?

Check that the hose is fully seated on the pump outlet and not kinked inside the tank. Listen for the motor running when you hit the spray button—if you hear nothing, verify the electrical connector is fully seated and the fuse is good.