Series 60 – Section 4.2 Water Pump (Gear-Case Mounted – 1991 and Later) (GCM)

Section 4.2
Water Pump (Gear-Case Mounted - 1991 and Later) (GCM)

The centrifugal-type water pump circulates the engine coolant through the cooling system.‪

The pump is mounted on the rear of the gear case on engines built after 6R37023, and is driven by the water pump drive gear. See Figure "Water Pump Mounting (1991 and Later Model)" . The water pump drive gear meshes with the bull gear. The pump was mounted on the front of the gear case cover on units built prior to and including 6R37023. See Figure "Front Mounted Water Pump " . Refer to "4.3 Water Pump (Front Mounted) (Fm)" .‪

Figure 1. Water Pump Mounting (1991 and Later Model)

An impeller is pressed on one end of the stainless steel drive shaft. The other end of this shaft has internal threads, and a retaining bolt secures the water pump drive gear to the shaft. Two tapered roller bearing assemblies are used to support the shaft. See Figure "Water Pump Details and Relative Location of Parts (Gear Case Mounted (GCM)" .‪

An O-ring, located in a groove in the water pump housing, seals the water pump to the gear case. An O-ring, located under the water pump cover, seals the cover to the water pump housing. The water pump bearings are lubricated by splash oil through a passage from the front of the pump housing.‪

An oil seal is located behind the bearing assemblies, and a unitized, spring-loaded, face-type water seal is used behind the impeller. This seal prevents water from leaking down the shaft and into the gear case. It also prevents lubricating oil from entering the cooling system. The water and oil seals cannot be replaced without removing the water pump from the engine.‪

1. Retaining Bolt‪	11. Oil Seal‪
2. Washer‪	12. O-ring Seal‪
3. Gear, Water Pump Drive‪	13. Drain Cock‪
4. Snap Ring‪	14. Housing, Water Pump‪
5. Bearing Race‪	15. Pipe Plug, Water Pump Housing‪
6. Roller Bearing, Small‪	16. Water Seal‪
7. Spacer Rings (2)‪	17. Impeller‪
8. Roller Bearing, Large‪	18. O-ring, Water Pump Cover‪
9. Bearing Race‪	19. Water Pump Cover‪
10. Drive Shaft‪	20. Snap Ring, Water Pump Cover‪

Figure 2. Water Pump Details and Relative Location of Parts (Gear Case Mounted (GCM)

Section 4.2.1
Repair or Replacement of Water Pump (GCM)

To determine if repair or replacement is necessary, perform the following procedure. See Figure "Flowchart for Repair or Replacement of Water Pump (GCM)" .‪

Figure 3. Flowchart for Repair or Replacement of Water Pump (GCM)

Section 4.2.2
Draining and Removal of Water Pump (GCM)

Drain the cooling system as follows:‪

Open the drain cocks located at the right rear corner of the engine, at the bottom of the water pump and in the bottom of the thermostat housing.‪

Remove the water pump as follows:‪

1. Loosen the hose clamps and remove the coolant hoses from the water pump housing.
2. Loosen and remove the three water pump housing-to-gear case bolts. Remove the water pump from the engine by pulling it straight out of the gear case.

Section 4.2.3
Disassembly of Water Pump (GCM)

Disassemble the water pump as follows:‪

EYE INJURY ‪
To avoid injury from flying parts when working with components under spring tension, wear adequate eye protection (face shield or safety goggles).‪

1. Remove water pump cover snap ring with snap ring pliers, (J–22380) or equivalent. Remove water pump cover and seal ring.

   NOTICE:
   When clamping gears, use soft jaws on vise to prevent damage to the gear teeth.‪

2. Clamp the water pump drive gear in a vise with the impeller facing up. Use a two-screw gear puller and remove the water pump impeller from the shaft, using the two threaded holes in the impeller.
3. Hold square end of water pump shaft and remove water pump drive gear retaining bolt and washer. See Figure "Water Pump Drive Gear Retaining Bolt Removal (GCM)" .
   

   Figure 4. Water Pump Drive Gear Retaining Bolt Removal (GCM)

4. Use a two-jaw gear puller to remove the water pump drive gear from the drive shaft.
5. Remove the snap ring from the water pump housing. See Figure "Snap Ring Removal (GCM)" .
   

   Figure 5. Snap Ring Removal (GCM)

6. Support the water pump housing, using steel blocks or plates; allow at least 76 mm (3 in.) of clearance between the pump housing and the press bed.
7. Press the drive shaft and bearings assembly out through the front (engine side) of the water pump housing, until both bearing races are clear of the housing.

   Note: Once the bearing assemblies are pressed out of the water pump housing, they must be replaced with new assemblies.

   NOTICE:
   Do not allow brass drift to score housing bore when tapping out seals. A scored bore will cause coolant leaks and can damage engine.‪

   CHEMICAL BURNS ‪
   To avoid injury from chemical burns, wear a face shield and neoprene or PVC gloves when handling fluoroelastomer O-rings or seals that have been degraded by excessive heat. Discard gloves after handling degraded fluoroelastomer parts.‪

8. Remove both the water and oil seals from the housing using a brass drift and hammer.
9. Support the drive shaft assembly on two steel blocks, at the bearing inner race.
10. Insert J–35988–3A (part of tool set J–35988–C) in end of drive shaft. See Figure "Removing Bearing Assemblies" .
    

    Figure 6. Removing Bearing Assemblies

11. Press the drive shaft out until it is clear of both bearing and race assemblies. Discard the used bearings, races, and the two spacer rings located between the bearing packs.

Section 4.2.3.1
Inspection of Water Pump (GCM)

Visually inspect the parts for cracks, wear or other damage. If parts are cracked, worn, or other damage is evident, replace damaged or worn parts. If no damage is found, reuse remaining components.‪

Section 4.2.4
Cleaning of Water Pump (GCM)

Clean the water pump as follows: ‪

1. Wash all of the pump parts in clean fuel oil.

   EYE INJURY ‪
   To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.‪

2. Dry the parts with compressed air.

Section 4.2.5
Assembly of Water Pump (GCM)

Assemble the water pump as follows:‪

1. Coat the bearing bores of the water pump housing and the drive shaft bearing surfaces with clean engine oil.

   NOTICE:
   Although the bearings are identical, the bearings and races are matched parts, and should be installed as they are removed from the box. Parts that are not matched will cause damage to the water pump.‪

2. Assemble the new bearing packs, as follows:
   1. Place the small spacer ring on the inner bearing race. See Figure "Bearing Pack Assembly (GCM)" .
   

   Figure 7. Bearing Pack Assembly (GCM)

   2. Place the larger spacer ring on the outer bearing race.
3. Install J–35988–18 into the center of J–35988–2 (parts of tool set J–35988–C) . See Figure "Bearing Installation Set-up (GCM)" .
   

   Figure 8. Bearing Installation Set-up (GCM)

4. Install J–35988–3A (part of tool set J–35988–C) on the end of the water pump shaft. Install the assembled bearing packs to the drive shaft. See Figure "Bearing Placement (GCM)" .
   

   Figure 9. Bearing Placement (GCM)

5. Center the small end of J–35988–1 (part of tool set J–35988–C) on the bearing inner race. Press the bearing pack onto the shaft until it contacts the shoulder of the shaft. Remove the tool used to pilot the bearings. See Figure "Bearing Installation (GCM)" .
   

   Figure 10. Bearing Installation (GCM)

6. Remove the shaft and bearing assembly from the press.

Section 4.2.5.1
Test Bearing Assembly

Test bearing assembly as follows:‪

1. Turn bearings to ensure they turn freely.
2. If bearings bind, disassemble water pump and replace bearing assembly. Refer to "4.2.3 Disassembly of Water Pump (GCM)" .

Section 4.2.6
Assembly of Water Pump (GCM)

Continue assembling the water pump, as follows:‪

1. Coat the oil seal contact area of the water pump housing with a thin film of clean engine oil. See Figure "Oil Seal Contact Area Lubrication (GCM)" .
   

   Figure 11. Oil Seal Contact Area Lubrication (GCM)

2. Install a new oil seal into the water pump housing from the front (gear side). See Figure "Oil Seal Positioning (GCM)" .
   

   Figure 12. Oil Seal Positioning (GCM)

   NOTICE:
   The contact surface of the oil seal is coated with a special sealant. Do NOT remove this sealant before installing the oil seal. If sealant is removed, leakage can occur.‪

3. Place the small end of J–35988–1 (part of tool set J–35988–C) into the water pump housing until it contacts the oil seal. See Figure "Oil Seal Installation (GCM)" .
   

   Figure 13. Oil Seal Installation (GCM)

4. Press the oil seal into the housing until the seal lip is bottomed in the pump housing. Remove the J–35988–1 (part of tool set J–35988–C) .
5. Coat the bearings with clean engine oil.
6. Place the water pump housing, with the gear side up, on a press bed.
7. Install the drive shaft, with bearings installed, to the water pump housing. See Figure "Drive Shaft Insertion (GCM)" .

   Note: During the bearing installation, the water pump housing must be parallel to the press bed or table surface.

   

   Figure 14. Drive Shaft Insertion (GCM)

8. Place the large end of J–35988–1 (part of tool set J–35988–C) over the drive shaft so that the lip of the tool rests squarely on the outer bearing race. See Figure "Drive Shaft Installation (GCM)" .

   NOTICE:
   The drive shaft must be installed using the outer bearing race only. Any other attempt at installation may damage the bearings.‪

   

   Figure 15. Drive Shaft Installation (GCM)

9. Press the drive shaft and bearing assembly into the water pump housing, using J–35988–1 (part of tool set J–35988–C) until it is seated firmly against the shoulder in the housing.
10. Install the snap ring to the water pump housing. See Figure "Snap Ring Installation (GCM)" .
    

    Figure 16. Snap Ring Installation (GCM)

    NOTICE:
    Apply sealant sparingly. Use of excess sealant may result in seal failure due to contamination of the sealing faces, which may cause pump leakage.‪

11. Turn the water pump housing over and check to make sure no residual sealant remains in the water seal bore or on the seal flange contact surface. Remove any residual sealant found in these areas. Working through the rear, apply a new coating of aviation Form-A-Gasket Number 3 or equivalent to the area where the water pump seal case contacts the pump body. See Figure "Water Pump Housing Seal Bore (GCM)" .
    

    1. Seal Bore‪

    2. Water Pump Housing‪

    Figure 17. Water Pump Housing Seal Bore (GCM)

12. Install J–35988–3A (part of tool set J–35988–C) to the fixture tool. See Figure "Support Installation (GCM)" .
    

    Figure 18. Support Installation (GCM)

    NOTICE:
    The extension must contact and support the shaft when installing the water seal and impeller to prevent damage to the bearings.‪

13. Install the water pump housing assembly to the fixture. See Figure "Water Pump Impeller Installation Set-up (GCM)" .
    

    Figure 19. Water Pump Impeller Installation Set-up (GCM)

14. Turn the adjustor wheel to raise the extension until it contacts the drive shaft in the water pump housing.
15. Apply Loctite® primer (Locquic Primer N, Part No. 764) by swabbing onto the I.D. of the rotor of the seal.
16. Install a new water seal over the drive shaft and seat it in the water pump housing. See Figure "Water Seal Insertion (GCM)" .
    

    Figure 20. Water Seal Insertion (GCM)

Detroit Diesel previously released a water pump coolant seal which required the use of seal installer (J–35517–1A, part of tool set J–35988–C) . This seal went into effect with engine serial number 06R670637 thru 06R698567 for On-Highway applications, and can be used with both the former style (front mounted) water pump as well as the current style (gear case mounted) water pump. The former coolant seal is no longer serviced. The new coolant seal is used after engine serial number 06R698567 for On-Highway applications. The new coolant seal requires the use of seal installer (J–35988–19) ; do not use seal installer (J–35517–1A) with the new coolant seal.‪

17. Position J–35988–19 (part of tool set J–35988–C) over the water seal. See Figure "Water Seal Installation (GCM)" .

    NOTICE: ‪

    Using old water pump seal installer (J–35517–1A, part of tool set J–35988–C) on the new water pump coolant seal will result in damage to water pump.‪

    

    Figure 21. Water Seal Installation (GCM)

18. Press the water seal into the housing until the flange of the seal case contacts the water pump housing a full 360 degrees. Remove J–35988–19 (part of tool set J–35988–C) .
19. With the water pump housing still housed in J–35988–2 (part of tool set J–35988–C) and located on a press bed, position the impeller over the square end of the drive shaft with the vanes of the impeller facing down. See Figure "Water Pump Impeller Installation (GCM)" .
    

    Figure 22. Water Pump Impeller Installation (GCM)

    NOTICE:
    During this procedure, the drive shaft must be supported by the extension tool (J–35988–3A, part of tool set J–35988–C) . Failure to support the drive shaft while installing the impeller may result in bearing damage.‪

20. Using the impeller installation tool (J–35988–14, part of tool set J–35988–C) , press the impeller on until the tool is flush against the water pump body. See Figure "Water Pump Impeller Location (GCM)" .
    

    Figure 23. Water Pump Impeller Location (GCM)

21. Turn the housing over and place it face (impeller side) down on fixture (J–35988–2, part of tool set J–35988–C) . See Figure "Water Pump Drive Gear Installation (GCM)" .

    NOTICE:
    If the gear has a press fit, turn the adjustor wheel to raise the extension (J–35988–3A, part of tool set J–35988–C) until it contacts and supports the shaft. This is necessary to prevent damage to the bearings when pressing the gear onto the shaft.‪

    

    Figure 24. Water Pump Drive Gear Installation (GCM)

22. Install the water pump drive gear to the drive shaft.

    Note: The water pump drive gear may have a slip fit. This is due to manufacturing tolerances and is acceptable.

23. Using the small end of J–35988–1 (part of tool set J–35988–C) , press the drive gear down onto the drive shaft until it touches the bearings. See Figure "Water Pump Drive Gear Installation (GCM)" .
    

    Figure 25. Water Pump Drive Gear Installation (GCM)

24. Install the retaining bolt and washer. Hold the square end of the drive shaft and torque the retaining bolt to 101-126 N·m (75- 93 lb·ft).

Section 4.2.6.1
Assembly Integrity Test

Verify the assembly integrity as follows:‪

1. Turn the pump over and install the water pump impeller slip and lash tester (J–35687–1) into the tapped holes provided in the impeller.

   NOTICE:
   When clamping gears, use soft jaws on vise to prevent damage to the gear teeth.‪

2. Clamp the water pump drive gear in a vise, with the impeller facing up.
3. Using a 1/2 in. drive torque wrench in the hole provided in the center of the slip and lash tester (J–35687–1) , apply 68 N·m (50 lb·ft) torque in either direction. The impeller must withstand 68 N·m (50 lb·ft) torque without slipping.
   1. If the torque specification is not satisfied, disassemble water pump and replace the impeller. Refer to "4.2.3 Disassembly of Water Pump (GCM)" .
   2. If the torque specification is satisfied, reuse the part.
4. Using a dial indicator with magnetic base, measure the total run-out of the water pump drive gear at four places, at 90° intervals. Maximum allowable run-out is 0.0635 mm (0.0025 in.). See Figure "Measuring Water Pump Drive Gear Runout (GCM)" .
   1. If this value is exceeded, disassemble the water pump and check for burrs or foreign particles. Refer to "4.2.3 Disassembly of Water Pump (GCM)" .
   2. If the value is not exceeded, reuse the part.
   

   Figure 26. Measuring Water Pump Drive Gear Runout (GCM)

5. Remove dial indicator and magnetic base.

Section 4.2.7
Assembly of Water Pump (GCM)

Continue assembly of the water pump as follows:‪

EYE INJURY ‪
To avoid injury from flying parts when working with components under spring tension, wear adequate eye protection (face shield or safety goggles).‪

1. Install seal ring, water pump cover, and snap ring with the beveled side of snap ring facing out.
2. Tap around the inside rim of the snap ring with a brass drift and hammer to seat snap ring in groove fully.

Section 4.2.8
Installation of Water Pump (GCM)

Install the water pump as follows:‪

1. Coat the water pump seal ring with clean engine oil.
2. Install the seal ring to the groove in the water pump housing.
3. Coat the water pump drive gear with clean engine oil.
4. Install the water pump to the engine, meshing the water pump drive gear with the bull gear.
5. Install the three water pump housing-to-gear case bolts. Tighten the bolts alternately and evenly to draw the water pump straight into the engine. Torque the bolts to 58-73 N·m (43-54 lb·ft).
6. Measure the gear backlash. Refer to "1.24.2.1 Check Engine Timing" .
7. Install water bypass tube. If using a spring type hose clamps, refer to step 8 . If using worm screw drive, liner type hose clamps, refer to step 9 .

   EYE INJURY ‪
   To avoid injury from flying parts when working with components under spring tension, wear adequate eye protection (face shield or safety goggles).‪

8. If spring type hose clamps are used, fasten the bypass tube to the water pump bypass outlet and thermostat housing water inlet as follows:
   1. Using the hose clamp installer tool (J–41454) , install two hose clamps onto the water bypass tube; then push a connecting hose onto each end of the bypass tube. See Figure "Clamp Installer Tool" . Using hose clamp installer tool (J–41454) , open the clamps and slide them over the hoses to secure them in place on the tube.
   

   Figure 27. Clamp Installer Tool

   Note: Ensure the clamps are seated against the beads on the bypass tube neck and are at least one-half inch from the hose ends.

   2. Using J–41454 (if required), install one clamp over the water bypass outlet on the water pump and one clamp over the thermostat housing water inlet.
   3. Push one end of the bypass tube and hose assembly onto the water pump bypass outlet and the other end onto the thermostat housing water inlet, ensuring the tube is properly oriented to avoid interference.
   4. Using the installer (J–41454) , open the clamps and slide them over the hoses to secure them in place on the water pump bypass outlet and the thermostat housing inlet.

   Note: Ensure the clamps are seated against the beads on the water pump bypass outlet and the thermostat housing water inlet and are at least one-half inch from the hose ends.

   5. Proceed to step 10 .
9. If worm screw drive, liner type clamps are used, fasten the bypass tube to the water pump bypass outlet and the thermostat housing water inlet as follows:
   1. Install two hose clamps onto the water bypass tube and push connecting hoses onto the ends of the tube.
   2. Push the hoses on the ends of the bypass tube onto the thermostat housing water inlet and the water pump bypass outlet, ensuring the tube is properly oriented to avoid interference.
   3. Secure the clamps onto the hoses and secure the hoses to the bypass tube, thermostat housing water inlet, and water pump bypass outlet by tightening the clamp screws.

   Note: Ensure the clamps are seated against the beads on the bypass tube neck; the thermostat housing water inlet, and the water pump bypass outlet, are at least one-half inch from the hose ends.

10. Fasten the water transfer tube to the water pump and oil cooler housing as follows:
    1. Install four worm screw drive hose clamps onto the water transfer tube and push connecting hoses onto the ends of the tube.
    2. Push the hoses on the ends of the transfer tube onto the oil cooler water inlet and the water pump outlet, ensuring the tube is properly oriented to avoid interference.
    3. Secure the ends of the hoses to the transfer tube, oil cooler inlet, and water pump outlet by tightening the clamp screws.
11. Refer to "12.3.5 Cooling System" for verification of proper water pump installation.