Will this pump work with my existing washer fluid hose and connectors?

Yes — the outlet port is sized for standard washer hose. Check that your existing hose isn't cracked before reinstalling it; old hose can fail once pressure is restored.

Do I need to drain the reservoir before pulling out the old pump?

It's easier if you do. Drain or siphon out the old fluid first, then remove the pump from the top or side of the tank depending on your reservoir design. You'll have less mess and a cleaner install.

What if the pump doesn't spray after installation?

Check your electrical connection first — make sure the connector is seated fully and the truck is running when you test it. If power is reaching the pump and it still won't spray, your hose may be kinked or pinched under the reservoir.