ACDelco 251-503 Engine Water Pump

Description:

Features and Benefits:

• Coated seals with a stainless steel spring for durability
• GM-recommended replacement part for your GM vehicle's original factory water pump
• Heat-treated impeller shafts supported by high-quality ball/roller bearings for smooth, reliable operation in virtually all conditions
• Manufactured to GM OE specification for fit, form, and function
• Offering the quality, reliability, and durability of GM OE
• Thoroughly tested for reliable, leak-free performance
• Uniform wall sections and smooth coolant-flow cavities for efficient operation

Specifications:

Features and Benefits:

• – A stain around the weep hole is acceptable. However, if a weep occurs with the engine running and the coolant system pressurized, then the water pump should be replaced.
• – After installation, pressure-test the system for leaks and check for sufficient fan blade clearance between the blade and radiator shroud.
• – Clean all excess dirt and debris from the water pump housing.
• – Clean all sealing surfaces, and make sure all old gasket material is removed before installing your replacement component.
• – Clean and reinstall the coolant recovery reservoir before flushing the cooling system.
• – Do not use any non-approved flush agents, and replace the coolant according to manufacturer's specifications.
• – Ensure that your engine fan pulley (or clutch, if used) is seated properly on the pump's shaft. If the fan wobbles during rotation, vibration resulting in premature bearing wear may occur. Also check the fan clutch for wear and replace as necessary.
• – Flush the cooling system completely, using power flush equipment or thermal cycling the system with clean water three times. The most effective method of system flushing is to use a coolant exchanger, following the manufacturer's operating instructions.
• – Flush your cooling system whenever the water pump or other system components are replaced. This will help prevent contamination from entering the system, which may result in repeated failure.
• – Inspect for leakage at the water pump outlet housing or the rear cover gasket, and leakage at the water pump vent or weep hole.
• – Inspect related components in the cooling system, including your fan blades, fan clutch, engine mounts, radiator, belts and hoses, and reservoir.
• – Inspect the fan blade. If damage is not detected, bent blades, loose rivets, and cracks may result in premature bearing failure. If damage is found, do not try to repair the fan-the part should be replaced.
• – Inspect the thermostat and radiator cap. Examine your thermostat and radiator cap, and replace if they show signs of sticking or leaking.
• – Never overtighten your drive belts. Belts that are too tight may cause an overload on pump bearings, greatly reducing the life of the water pump.
• – Never strike the water pump shaft, since this will damage the new water pump.
• – Run your vehicle to increase engine temperature, and ensure the system is pressurized.
• – Torque all bolts according to the manufacturer's specifications, and adjust belts to proper tension (if applicable) to manufacturer's specifications.
• – Use sealant tabs only if recommended. Some sealant tabs or similar compounds may restrict coolant flow through the passages of some cooling systems.
• – Utilize quality coolant when refilling your cooling system with the recommended 50/50 coolant/water mix. Distilled water should be used, as hard tap water can leave mineral deposits in the cooling system and reduce coolant flow, or result in corrosion and seal damage. Contaminated or depleted coolant can also result in corrosion and seal damage, and lead to pump failure. Take care to select the correct coolant for your vehicle by consulting the vehicle manufacturer's service information.
• – With the new pump installed, turn the hub by hand and check for rotation.
• Tips for Water Pump Inspection:
• Tips for Water Pump Servicing & Installation:
• Tips to Help Prevent Water Pump Failure:

Specifications: