Series 55 – Section 4.2 Water Pump

Section 4.2
Water Pump

The water pump circulates engine coolant through the cooling system.‪

Section 4.2.1
Replacement of Water Pump

To determine if pump replacement is necessary, perform the following procedure. See Figure "Water Pump Replacement Flowchart" .‪

Figure 1. Water Pump Replacement Flowchart

Section 4.2.2
Removal of Water Pump

Remove water pump as follows:‪

1. Remove the fan, fan hub, and fan belts. Refer to OEM guidelines. Refer to "4.5.2 Removal of Engine Cooling Fan" for removal.
2. Drain the cooling system by removing the lower plugs in the water pump and oiler cooler housing. Refer to "13.4.4 Cooling System" .
3. Remove the thermostat housing and thermostats. Refer to "4.3.3 Draining and Removal of Thermostat" .
4. Remove the water pump inlet tube. See Figure "Removal of Water Pump Inlet Tube " .
   

   1.Mounting Bolts (2)‪	4.Bypass Tube‪
   2.Outlet Flange‪	5.Gasket‪
   3.Pipe Plugs‪	6.Water Pump Assembly‪

   Figure 2. Removal of Water Pump Inlet Tube

5. Remove the water pump bolts from the engine block. See Figure "Removal of Water Pump" .
   

   1.Water Pump Assembly‪	4.Long Mounting Bolts‪
   2.Gasket‪	5.Short Mounting Bolt‪
   3.Cylinder Block‪	‪

   Figure 3. Removal of Water Pump

6. Remove the water pump.
7. Remove the water pump gasket. See Figure "Removal of Water Pump" .
   

   1.Water Pump Assembly‪	4.Long Mounting Bolts‪
   2.Gasket‪	5.Short Mounting Bolt‪
   3.Cylinder Block‪	‪

   Figure 4. Removal of Water Pump

Section 4.2.2.1
Inspection of Water Pump

Inspect the water pump as follows.‪

1. Inspect the water pump for external leaks.
2. If a leak is detected, the water pump must be replaced.
3. If a leak wasn't found, reuse the water pump.

Section 4.2.3
Installation of Water Pump

Install the water pump as follows:‪

1. Install new water pump gasket.
2. Install the water pump using the nine water pump bolts.
3. Torque the bolts to 30-38 N · m (22-28 lb · ft).
4. Install a new gasket, and bolt the inlet tube to the water pump housing. Torque the bolts to 45-55 N · m (33-41 lb · ft).
5. Install the thermostat housing and thermostats. Refer to "4.3.4 Installation of Thermostat" .
6. Install the fan, fan hub, and fan belts. Refer to OEM guidelines.
7. Install and close the water pump and thermostat housing drain plugs, and refill the engine with coolant.