Cardone Select 55-21313 New Water Pump Unitized seals produced with superior materials drastically enhance operating life. Hubs and impellers are precisely perpendicular to the bearing shaft to eliminate vibration. Manufactured to original casting specifications; bearing type (ball/roller vs. ball/ball) and materials meet or exceed original specifications. Applications are not over consolidated, and are precision machined ensuring proper fit. 100% tested for maximum performance and durability. A cooling system maintenance check should be performed at least once every two years. Consult vehicles service manual for specific guidelines on cooling system. A hydrometer can be used to measure specific gravity of coolant. A refractometer can be used to determine coolant concentration and freeze point. For most modern vehicles, knowing the engine size is sufficient to locate the correct replacement water pump. However, with some older passenger vehicles and medium duty applications, you may need an identification number that is either stamped on the original casting or attached on a metal tag. You may also need a specific dimension off of the original pump to correctly identify the replacement pump. Always refer to the catalog for details on how to correctly identify the water pump for your application.