950G Wheel Loader and 962G Wheel Loader Electrohydraulic System Caterpillar

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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 speed tests, the bucket must be empty. If the machine is equipped with the optional ride control system, place the ride control switch in the OFF position.

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

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

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

3. Shift the transmission to neutral.

4. Start the engine and warm the hydraulic oil to normal operating temperature. The hydraulic oil must be at a temperature of 54° to 82°C (129° to 180°F) in order to obtain accurate results.

5. Position the bucket so that the bottom of the bucket is flat on the ground.

6. Increase the engine RPM to high idle. Maintain high idle RPM for duration of the test.

7. Move the lift control lever to the LIFT 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 LIFT position.

   The times in the following table are for a machine with a general purpose bucket.

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   Table 1

   Cycle Time for Lift Cylinders	Model	Time
   RAISE from ground to lift kickouts (empty bucket)	950G/962G	6.3 ± 0.4 seconds
   	IT62G	5.8 ± 0.4 seconds

8. Raise the bucket to the maximum height. Tilt back the bucket as far as possible.

9. With the engine at high idle, move the tilt control lever to the full DUMP position. Hold the tilt control lever in this position until the bucket is at the full dump position. Record the time to the full dump position.

   The time in the following table is for a machine with a general purpose bucket.

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   Table 2

   Cycle Time for Tilt Cylinder	Time
   DUMP from full tilt back position to full dump position (empty bucket at maximum height)	2.0 ± 0.5 seconds

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

1. Check performance 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.

2. 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.

3. 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.

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

5. Check the valve spools in the lift control valve and in the tilt control valve.

6. Check the piston seals in the cylinders.