302.5C Mini Hydraulic Excavator Hydraulic System Caterpillar

Measuring the swing speed and the overswing of the machine will determine if there is a need to check the swing motor.

Note: The engine speed and/or the machine configuration that is used during this test can affect the results of this test. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for the engine speed that was used for this test.

Note: The relief valve pressure settings must be set to the relief valve pressure specification before performing this operational check. Refer to Testing and Adjusting, "Specifications".

Table 1

Required Tools
Description	Qty
Tape Measure	1
Stopwatch	1

Illustration 1	g00816368

1. Position the machine on level ground. Refer to Illustration 1.

2. Fully retract the stick cylinder and fully extend the bucket cylinder.

3. Stop the engine.

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Illustration 2	g00293972
(A) Upper frame (B) Undercarriage frame (C) Marking

4. To indicate the relationship of the two positions, put a mark (C) on the inner race and the outer race of the swing bearing. The mark will be used as a target to stop the swing operation. Refer to Illustration 2.

5. Start the engine.

6. Place the engine speed dial in the HIGH IDLE position.

7. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

8. Load the bucket.

   Weight of bucket load ... 105 kg (231.5 lb)

9. Move the swing joystick in either direction until the machine completes a 90 degree swing operation away from the target.

10. Move the swing joystick in the opposite direction until the machine completes a 90 degree swing operation toward the target. Return the swing joystick to the NEUTRAL position at the target.

11. Measure the amount of overswing by measuring the distance between the marks on the swing bearing. Refer to Illustration 2.

    Note: Use a point that is visible from the operator seat as a reference point for the target.

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    Table 2

    Overswing
    Item	Specification
    Right Swing	190 mm (7.5 inch) or less
    Left Swing

12. Empty the bucket and reposition the machine according to Illustration 1.

13. Move the swing joystick in each direction and measure the time that is required to complete a 90 degree swing operation.

    Move the swing joystick in each direction and measure the time that is required to complete three revolutions.

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    Table 3

    Swing Time (1)
    Item	Specification
    Right Swing (90°)	2.0 sec or less
    Left Swing (90°)
    Continuous swing right (three revolutions) (2)	18.0 to 22 sec or less
    Continuous swing left (three revolutions) (2)

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    ( 1 )	Empty bucket
    ( 2 )	Start the measurement after the machine has rotated one full revolution.