2017-2025 6.6L L5P Duramax Water Pump Alliant AP63586

The Alliant Power AP63586 is a new water pump for 2017–2024 GM L5P Duramax applications. Alliant’s Engine Water Pump circulates coolant through the engine and cooling system.

Features & Benefits

New Alliant Power Water Pump (Alliant P/N AP63586)
Fit, form, and function tested to meet or exceed original-equipment standards (per Alliant Power)
Direct replacement for 12680257 / 251-801 / 251-817
Backed by Alliant Power’s 24-month, unlimited-mileage warranty

Application

Chevrolet Silverado 2500 HD / Silverado 3500 HD (2017–2024)
GMC Sierra 2500 HD / Sierra 3500 HD (2017–2024)
Chevrolet Silverado 4500 HD / Silverado 5500 HD / Silverado 6500 HD (2019–2024)

Always verify fitment against your VIN, engine, and OE part number before ordering.

Cross-Reference / Replaces

General Motors: 12680257
ACDelco: 251-801, 251-817
Navistar: 6040614, 6040614C, 6040614C91
Alliant Power: AP63586

Warranty: Alliant Power’s standard warranty: 24 months with unlimited miles/hours on installed parts (Alliant Power warranty policy, rev. Aug 2025).[...]