How to Change the Water Pump on a Cummins 5.9L Turbo Diesel
- 1). Remove the cable from the negative terminal of both batteries with a socket wrench. Place a drain pan under the radiator drain and remove the drain plug. Wait for the coolant to drain from the radiator and replace the drain plug.
- 2). Detach the electrical connectors from the air temperature sensor and the mass airflow sensor if your vehicle is so equipped. Detach the inlet tube for the turbocharger and remove the housing for the air filter with a socket wrench. Remove the alternator assembly.
- 3). Rotate the tensioner assembly clockwise with a long-handled wrench to relieve the tension on the accessory drive belt, then disconnect the belt. Remove the mounting bolts for the water pump with a socket wrench and disconnect the water pump from the engine. Remove and discard the O-ring from the water pump.
- 4). Install a new O-ring onto its mounting groove on the water pump. Install the water pump so that the weep hole on the water pump faces down. Torque the mounting bolts for the water pump to 18 foot-pounds with a torque wrench.
- 5). Install the accessory drive belt with a long-handled wrench. Connect the alternator assembly and torque its mounting bolts to 30 foot-pounds with a torque wrench. Install the air filter housing and attach the inlet tube for the turbocharger. Attach the electrical connectors to the air temperature sensor and mass airflow sensor.
- 6). Refill the radiator with coolant and connect the cables to the negative battery terminals with a socket wrench. Start the engine and allow it to warm up. Check and correct any coolant leaks.
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