How to change the water pump?

REMOVAL
The water pump can be removed and installed without discharging the air conditioning system (if equipped).

1. Disconnect battery negative cable.
2. Drain cooling system.
3. Do not waste reusable coolant. If solution is clean, drain coolant into a clean container for reuse. WARNING: CONSTANT TENSION HOSE CLAMPS ARE USED ON MOST COOLING SYSTEM HOSES. WHEN REMOVING OR INSTALLING, USE ONLY TOOLS DESIGNED FOR SERVICING THIS TYPE OF CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER 6094). SNAP-ON CLAMP TOOL (NUMBER HPC-20) MAY BE USED FOR LARGER CLAMPS. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CONSTANT TENSION CLAMPS. CAUTION: A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with matching number or letter.
4. Remove upper radiator hose clamp and hose at radiator.

5. The thermal viscous fan drive is attached (threaded) to the water pump hub shaft. Remove fan/viscous fan drive assembly from water pump by turning mounting nut counterclockwise as viewed from front. Threads on viscous fan drive are RIGHT HAND. A Snap-On 36 MM Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool Set number 2017DSP) and Special Tool 6958 Spanner Wrench with Adapter Pins 8346 can be used. Place Special Tool 6958 Spanner Wrench onto the water pump pulley with Adapter Pins 8346 inserted into the holes on the pulley to prevent pulley from rotating. Do not attempt to remove fan/viscous fan drive assembly from vehicle at this time.
6. If water pump is being replaced, do not unbolt fan blade assembly from thermal viscous fan drive.
7. Remove fan shroud attaching hardware (two bolts at bottom-two clips at top).
8. Remove fan shroud and fan blade/viscous fan drive assembly from vehicle as a complete unit.
9. After removing fan blade/viscous fan drive assembly, do not place thermal viscous fan drive in horizontal position. If stored horizontally, silicone fluid in viscous fan drive could drain into its bearing assembly and contaminate lubricant.
10. Remove the accessory drive belt.
11. Remove lower radiator hose clamp and remove lower hose at water pump.
12. Remove heater hose clamp and heater hose from heater hose coolant return tube.

13. Loosen heater hose coolant return tube mounting bolt and remove tube from water pump. Discard the old tube O-ring.
14. Remove seven water pump mounting bolts.
15. Loosen clamp at water pump end of bypass hose. Slip bypass hose from water pump while removing pump from vehicle. Discard old gasket. CAUTION: Do not pry water pump at timing chain case/cover. The machined surfaces may be damaged resulting in leaks.

CLEANING
Clean the gasket mating surface. Use caution not to damage the gasket sealing surface.

INSPECTION
Inspect the water pump assembly for cracks in the housing, Water leaks from shaft seal, Loose or rough turning bearing or Impeller rubbing either the pump body or timing chain case/cover.

INSTALLATION

1. Clean gasket mating surfaces.
2. Using a new gasket, install water pump to engine as follows: Guide water pump nipple into bypass hose as pump is being installed. Install water pump bolts. Tighten water pump mounting bolts to 40 Nm (30 ft. lbs.) torque.
3. Position bypass hose clamp to bypass hose.
4. Spin water pump to be sure that pump impeller does not rub against timing chain case/cover.
5. Install a new O-ring to the heater hose coolant return tube. Coat the new O-ring with antifreeze before installation.
6. Install coolant return tube and its mounting bolt to engine. Be sure the slot in tube bracket is bottomed to mounting bolt. This will properly position return tube.
7. Connect radiator lower hose to water pump.
8. Connect heater hose and hose clamp to coolant return tube.
9. Install accessory drive belt.
10. Position fan shroud and fan blade/viscous fan drive assembly to vehicle as a complete unit.
11. Install fan shroud.
12. Install fan blade/viscous fan drive assembly to water pump shaft.
13. Fill cooling system.
14. Connect battery negative cable.
15. Start and warm the engine. Check for leaks.