950G Series II Wheel Loader, 962G Series II Wheel Loader and IT62G Series II Integrated Toolcarrier Hydraulic System Implement Cycle Time - Check Caterpillar

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.

The implement cycle time can be checked in order to verify a complaint about slow implement speed. This test will also help to determine whether all functions are slow or only one function is slow.

Note: For all cycle time tests, the work tool must be empty.

Machine Preparation

1. Move the machine to an open area so that the work tool can be fully raised.

2. Park the machine on a smooth, level surface. Park the machine away from working machines and personnel. Lower the work tools to the ground.

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

4. Engage the parking brake.
   Show/hide table

   Illustration 1	g00914095

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

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

6. Perform the torque converter stall test in order to verify that the engine is developing adequate power.

   For more information about performing the torque converter stall test, refer to the Service Manual module Troubleshooting and Testing and Adjusting, RENR4310, "Torque Converter Stall - Check" for the machine that is being serviced.

7. Shift the transmission to neutral.

8. Start the engine. Warm the hydraulic oil to normal operating temperature. The hydraulic oil must be at a temperature of 65 ± 3°C (150 ± 5°F) in order to obtain accurate results.

Cycle Time Check

RAISE

1. Move the work tool to the TILT BACK position.

2. Lower the work tool completely.

3. Increase the engine RPM to high idle.

4. Move the lift control lever to the RAISE position. Hold the lift control lever in this position until the lift cylinder reaches the end of travel. Record the amount of time that is required for the work tool to travel from the ground to the full RAISE position.

   Refer to Table 1 for the correct cycle time for the machine that is being serviced.

LOWER

1. Position the work tool so that the work tool is flat on the ground.

2. Raise the work tool to the maximum height.

3. Move the work tool to the full TILTBACK position.

4. Increase the engine RPM to high idle.

5. Move the lift control lever to the full LOWER position.

   Note: Ensure that the lift control lever is not in the FLOAT position.

   Record the time from the full LIFT position to the ground.

   Refer to Table 1 for the correct cycle time for the machine that is being serviced.

DUMP

1. Position the lift linkage at the midpoint of travel. Tilt back the work tool as far as possible.

2. Increase the engine RPM to high idle.

3. Move the tilt control lever to the full DUMP position. Hold the tilt control lever in this position until the work tool is at the full DUMP position. Record the time to the full DUMP position.

   Refer to Table 1 for the correct cycle time for the machine that is being serviced.

TILT BACK

1. Position the lift linkage at the midpoint of travel.

2. Position the work tool in the FULL DUMP position.

3. Increase the engine RPM to high idle.

4. Move the tilt control lever to the full TILT BACK position. Hold the tilt control lever in this position until the work tool is against the stop. Record the time from the level position to the full TILT BACK position.

   Refer to Table 1 for the correct cycle time for the machine that is being serviced.

Possible Causes for Incorrect Times

If the times are not correct, check the following conditions:

1. Check the pressure setting of the main relief valve.

   Reference: For information on setting the pressure of the main relief valve, refer to the Service Manual module Testing and Adjusting, "Relief Valve (Main)" for the machine that is being serviced.

2. Check the pressure setting of the line relief valves.

   Reference: For information on setting the line relief valves, refer to the Service Manual module Testing and Adjusting, "Relief Valve (Line) - Test and Adjust" for the machine that is being serviced.

3. Check the condition of the implement pump.

   Reference: For information on checking the condition of the implement pump, refer to the Service Manual module Testing and Adjusting, "Pump Performance (Implement) - Test" for the machine that is being serviced.

4. Check the makeup valves in the lift control valve and in the tilt control valve.

5. Check the spools in the main control valve for proper movement.

6. Check the piston seals in the cylinders.