308D CR 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 or the anti-reaction valve. The fine swing control switch (if equipped) must be in the OFF position.

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. Refer to Testing and Adjusting, "Operational Checks" for the machine configurations that were 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
Measuring Tape	1
Stopwatch	1

Illustration 1	g00297618

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

2. Stop the engine.

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

3. 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.

4. The bucket should be empty.

5. Move the swing joystick in either direction until the machine completes a 180 degree swing operation away from the target.

6. Move the swing joystick in either direction until the machine completes a 180 degree swing operation toward the target. Return the swing joystick to the NEUTRAL position at the target.

7. 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	New	Rebuild	Service Limit
   Right Swing	650 mm (25.6 inch) or less	710 mm (28.0 inch) or less	830 mm (32.7 inch) or less
   Left Swing

8. Move the swing joystick in each direction and measure the time that is required to complete a 180 degree swing operation.
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   Table 3

   Swing Time
   Item	New	Rebuild	Service Limit
   Right Swing	5.0 seconds or less	6.5 seconds or less	7.5 seconds or less
   Left Swing