980G Series II Wheel Loader Electrohydraulic System Caterpillar

Show/hide table

Rotating fan blades can result in personal injury or death. Stop the engine and allow the fan to come to a complete stop before making any test or adjustment. Before starting the engine, make sure all of the finger guards are installed securely. Do not allow any tools or test equipment to protrude or vibrate into the path of the rotating fan blades.

Show/hide table

Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

Show/hide table

Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine. To prevent personal injury or death, perform the following: Park the machine on a smooth, level surface. Lower the work tool to the ground and engage the parking brake. Stop the engine and remove the key. Block the wheels and install the steering frame lock.

Machine Preparation

1. Move the machine to a smooth horizontal location. Move away from working machines and personnel. Lower the work tools to the ground.

2. Allow only one operator on the machine. Keep all personnel away from the machine or in the view of the operator.

3. Engage the parking brake.

Show/hide table



Illustration 1	g00893065

4. Place the steering frame lock in the LOCKED position.

   Reference: For information about preparing a machine for troubleshooting, refer to the Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.

5. In order to check the speed of the hydraulic fan motor, use a 9U-7400 Multitach. The multitach measures the hydraulic fan rpm by using reflective tape and a photo pickup.

   Reference: Special Instruction, NEHS0605, "9U-7400 Multitach II Group and 9U-7402 Multitach II Group"

   Note: If a piece of reflective tape is already visible on one of the fan blades, proceed to Step 6. If no reflective tape is visible on one of the fan blades, use the following procedure:

   Show/hide table
   
   

   Illustration 2	g00799694
   Side View of the Radiator Group

   1. Ensure that the key start switch is in the OFF position. Access to the fan blade is through door (1) on either side of the radiator group.

   2. Clean a small area on the surface of one fan blade. Position the reflective tape so that the tape is completely visible. Then attach a piece of the reflective tape to the fan blade.

Show/hide table



Illustration 3	g00815885

6. Place photo pickup (2) into the holder on magnetic base (3) and tighten the screw. Attach magnetic base (3) to the fan guard assembly.

7. When the reflective tape and photo pickup (2) are in alignment, the LED indicator (red light) will come on. Position photo pickup (1) accordingly.

   Note: When you start the engine, vibration of the machine may cause the photo pickup to become misaligned. It may be necessary to adjust the position of magnetic base (3) in order to realign photo pickup (2) .

Testing and Adjusting Fan Speed

1. Start the engine. Run the engine at high idle. Move the control levers in all directions in order to warm the hydraulic oil to normal operating temperature 49 to 65°C (120 to 150°F).

   Note: In order to check the fan speed at low idle, the following conditions must be met:

   • The engine coolant must be less than 89 °C (192 °F).

   • The temperature of the air inlet manifold must be less than 50 °C (122 °F).

   • The lube oil temperature for the transmission must be less than 93 °C (199 °F).

   • The temperature of the hydraulic oil sump must be less than 90 °C (194 °F).

2. Run the engine at low idle. Observe the multitach (4) and record the hydraulic fan speed.

   Refer to Table 2 for the hydraulic fan speed and the engine speed for the machine that is being serviced.

Show/hide table



Illustration 4	g00799925
Hydraulic Fan Pump

3. If the fan speed is not within the specifications, adjust the minimum fan speed. Use the adjusting screw (5) on the hydraulic fan pump in order to adjust the minimum fan speed. Torque for the locknut is 21 ± 2 N·m (15 ± 1.5 lb ft).

4. If any adjustments are made to the hydraulic fan system, repeat Step 1 through Step 3 until the minimum fan speed is properly adjusted.

Show/hide table



Illustration 5	g00799930
Solenoid Valve (Demand Fan)

5. The solenoid control valve (demand fan) is located on the right side of the engine and below the hydraulic fan pump. Turn the key start switch to the OFF position. Disconnect the electrical connection from the connection (7) on the solenoid valve.

   Note: Removing the connector from the solenoid valve will create a fault code CID 362. This fault code will be logged and need to be cleared after the testing is completed. The fault code can be cleared through Caterpillar Electronic Technician.

6. Start the engine and run the engine at high idle.

7. Observe the multitach (4) and record the hydraulic fan speed.

   Refer to Table 3 for the hydraulic fan speed and the engine speed for the machine that is being serviced.

8. If the speed of the fan is not within the specifications, adjust the maximum fan speed. Use adjusting screw (6) on the hydraulic fan pump in order to adjust the maximum fan speed. Torque for the locknut is 21 ± 2 N·m (15 ± 1.5 lb ft).

9. If any adjustments are made to the hydraulic fan system, repeat Step 6 through Step 8 until the maximum fan speed is properly adjusted.

10. Turn the key start switch to the OFF position. Connect the electrical connector to the connector on the solenoid valve (7).

11. Start the engine. Ensure that the hydraulic oil is at normal operating temperature.

12. Check the operation of the Demand Fan. Run the engine at high idle.

13. In order to check the operation of the Demand Fan, one of the following conditions must be met.
    • The engine coolant must be greater than 89 °C (192 °F).

    • The temperature of the air inlet manifold must be greater than 50 °C (122 °F).

    • The lube oil temperature for the transmission must be greater than 93 °C (199 °F).

    • The temperature of the hydraulic oil sump must be greater than 90 °C (194 °F).

    Expect an increase of at least 100 rpm over the minimum setting.

14. If the Demand Fan is operating correctly, turn the key start switch to the OFF position and remove all the test equipment.

Show/hide table



Illustration 6	g00893707

15. Place the steering frame lock in the STORE position.