Repeatedly move the bucket into the LIFT position, into the LOWER position, into the DUMP position, and into the TILT position.
- Watch the cylinders during the extension and during the retraction. Cylinder movement must be smooth and regular.
- Listen for noise from the pump.
- Listen for the sound of the line relief valves. The line relief valves must only open during the full extension of the cylinders or during the full retraction of the cylinders. The line relief valves must only open when the bucket is empty.
- Watch the operation of the bucket positioner and lift kickout.
The lift control lever has detents in the RAISE position and in the FLOAT position.
The tilt control lever has a detent in the TILT position when the bucket is between full dumping and the necessary angle for digging.
Drift Tests for the Lift Cylinders and the Tilt Cylinders
The drift rates will change with different conditions of the hydraulic components. The drift rates will also change as a result of the operation, an empty bucket or a loaded bucket, the hydraulic oil temperature, and other conditions.
The values that are shown are for an empty bucket. Before the drift on the cylinder rod is measured, the cylinders must be extended at least five times. Check the oil temperature.
To check the lift circuit, the bucket should be lifted to the maximum height and the control lever should be moved to the HOLD position. Measure the distance of retraction by the cylinders. Check the time that elapsed. Make a comparison with the chart.
Note: The drift distances in the chart are for new machines.
| LIFT CYLINDER DRIFT | ||
| Maximum Drift | Oil Temperature | Time in Minutes |
20.0 mm (.8 inch) |
38 to 49°C (100 to 120°F) |
5.0 |
20.0 mm (.8 inch) |
49 to 66°C (120 to 150°F) |
2.7 |
20.0 mm (.8 inch) |
Above 66°C (150°F) |
1.7 |
To check the tilt circuit, lift the bucket to the maximum height. Move the lift control lever to the HOLD position. Activate the tilt circuit until the bucket is at the necessary angle for digging. Move the tilt control lever to the HOLD position. Measure the distance of retraction by the cylinders. Check the time that elapsed. Make a comparison with the chart.
| TILT CYLINDER DRIFT | ||
| Maximum Drift | Oil Temperature | Time in Minutes |
25.0 mm (1.0 inch) |
38 to 49°C (100 to 120°F) |
5.0 |
25.0 mm (1.0 inch) |
49 to 66°C (120 to 150°F) |
2.7 |
25.0 mm (1.0 inch) |
Above 66°C (150°F) |
1.7 |
If the drift rates are not correct, perform the following checks:
- Check the makeup valves in the control valve sections.
- Check the line relief valves in the control valve.
- Check the condition of the valve stems in the control valve sections.
- Check the piston seals in the cylinders.
Speed Test for the Lift Cylinders and the Tilt Cylinders
Start the engine. Run the engine at a high idle rpm. Repeatedly lift the arms and lower the arms in order to increase the hydraulic oil temperature. The temperature of the hydraulic oil must be more than 38°C (100°F).
Use a timer to measure the amount of time that elapses while the lift arms are moved up and down. Measure the time that elapses while the bucket is tilted in either direction.
When the empty bucket has been lowered to the ground and the engine is at a high idle rpm, move the lift control lever into the RAISE detent position. The lift arms require 12 to 13 seconds in order to reach the top of the lift kickout.
Raise the bucket until the lift arms are parallel to the ground. Move the bucket to the full TILT position. With the engine at a high idle rpm, move the lever to the DUMP position. Hold the lever in that position. The bucket requires 3.6 to 4.5 seconds in order to reach the stops.
If the travel times are not correct, perform the following checks:
- Check the pump efficiency.
- Check the setting of the relief valves.
- Check the makeup valves in the control valve sections.
- Check the valve stems in the control valve sections.
- Check the piston seals in the cylinders.