ACDelco 12551905 Engine Water Pump O-Ring
for 1999 GMC Sierra 1500

Description:

Features and Benefits:

• GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
• GM Genuine Parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
• GM regularly updates production and service part designs to integrate new materials and technologies
• Made from heat and chemical-resistant materials
• Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)
• Tips for Water Pump Inspection:
• – 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.
• – Clean all excess dirt and debris from the water pump housing.
• – Inspect for leakage at the water pump outlet housing or the rear cover gasket, and leakage at the water pump vent or weep hole.
• – Run your vehicle to increase engine temperature, and ensure the system is pressurized.
• Tips for Water Pump Servicing & Installation:
• – After installation, pressure-test the system for leaks and check for sufficient fan blade clearance between the blade and radiator shroud.
• – 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.
• – 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.
• – Inspect related components in the cooling system, including your fan blades, fan clutch, engine mounts, radiator, belts and hoses, and reservoir.
• – Never strike the water pump shaft, since this will damage the new water pump.
• – 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.
• – With the new pump installed, turn the hub by hand and check for rotation.
• Tips to Help Prevent Water Pump Failure:
• – 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 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 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.
• – 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.

Specifications:

Manufacturer Warranty: