303C CR and 303.5C CR Mini Hydraulic Excavators Hydraulic System Caterpillar

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
Tape Measure	1
Stopwatch	1

Test Procedure for Boom, Stick, and Bucket Cylinders

Illustration 1	g00816216

1. Start the engine.

2. Position the machine on level ground.

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

4. Load the bucket.

   Weight of bucket load ... 150 kg (331 lb)

5. Fully extend the bucket cylinder. Retract the bucket cylinder 10 mm (0.4 inch) from the fully extended state.

6. Fully retract the stick cylinder. Extend the stick cylinder 10 mm (0.4 inch) from the fully retracted state.

7. Raise or lower the boom until the bucket to stick pin is the same height as the boom foot pin. Refer to Illustration 1.

8. Measure the length of each cylinder from cylinder pin to cylinder pin.

9. Stop the engine.

10. Leave the machine in this position for 3 minutes. Measure the length of each cylinder length from cylinder pin to cylinder pin for drift.

Table 2

Cylinder Drift
Item	Specification
	303C CR	303.5C CR
Boom Cylinder	2 mm (0.1 inch) or less
Stick Cylinder	5 mm (0.2 inch) or less
Bucket Cylinder

Test Procedure for Blade Cylinder

Illustration 2	g00816222

1. Start the engine.

2. Position the machine on level ground.

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

4. Position the stick so that the stick is perpendicular to the ground. Lower the stick to the ground. Refer to Illustration 2.

5. Fully retract the blade cylinder. Extend the blade cylinder 10 mm (0.4 inch) from the fully retracted state.

6. Measure the length of the blade cylinder from cylinder pin to cylinder pin.

7. Stop the engine.

8. Leave the machine in this position for 3 minutes. Measure the length of the blade cylinder from cylinder pin to cylinder pin for drift.

Table 3

Cylinder Drift
Item	Specification
Blade Cylinder	303C CR	303.5C CR
	2 mm (0.1 inch) or less

Test Procedure for Boom Swing Cylinder

Illustration 3	g00816380
(A) 12 degrees

1. Start the engine.

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

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

4. Load the bucket.

   Weight of bucket load ... 150 kg (331 lb)

5. Position the machine on a slope of 12 degrees. Refer to Illustration 3.

6. Position the implements at maximum reach and close the bucket. Position the bucket above the ground so that the bucket will not come in contact with any obstacles.

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Illustration 4	g01154250

7. Position the upper structure at position (X). The upper structure should be at a 90 degree angle to the lower structure. Refer to Illustration 4.

8. Measure the length of the boom swing cylinder from cylinder pin to cylinder pin.

9. Stop the engine.

10. Leave the machine in this position for 3 minutes. Measure the length of the boom swing cylinder from cylinder pin to cylinder pin for drift.
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    Table 4

    Cylinder Drift
    Item	Specification
    	303C CR	303.5C CR
    Boom Swing Cylinder	2 mm (0.1 inch) or less