345D, 349D and 349D2 Excavators Hydraulic System Caterpillar

Specifications

Preparation

1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".
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   Illustration 1	g01128644
   Pump compartment (1) Pressure tap (delivery pressure for drive pump) (2) Pressure tap (power shift pressure) (3) Pressure tap (delivery pressure for idler pump)

4. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (3).
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   Illustration 2	g01128646
   Left swing motor (bottom view) (4) Pilot manifold (5) Connector

5. Disconnect connector (5) from pilot manifold (4).

6. Start the engine

   Note: Certain machines will default to "Economy Mode" at machine startup. Change to "High Hydraulic Power Mode" before performing the test procedure.

7. Place the machine controls at the following settings: Power Mode, engine speed dial "10" and AEC switch OFF.

   Note: The engine will not reach maximum no-load speed until the hydraulic tank pressure has reached the operating level.

   Reference: Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.

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

   Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.

Illustration 3	g01435105
Swing motors (top view) (6) Left swing motor (7) Right swing motor (15) Relief valve (left swing motor) (16) Locknut (17) Adjustment plug (18) Adjustment plug (19) Locknut (20) Relief valve (right swing motor) (28) Relief valve (right swing motor) (29) Locknut (30) Adjustment plug (31) Adjustment plug (32) Locknut (33) Relief valve (left swing motor)

Right Swing Motor

Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.

Note: A temporary setting of the relief valve pressures for the left swing motor is required to see the relief valve pressures of the right swing motor.

1. Loosen locknuts (16) and (19) on the left swing motor (6). Turn adjustment plugs (17) and (18) by one quarter turn clockwise.

2. Slowly move the swing control lever for a full right swing operation and check the pressure for relief valve (28) at pressure tap (3).

3. Return the swing control lever to the NEUTRAL position.

4. Loosen locknut (29) on the right swing motor (7). Turn adjustment plug (30) until the pressure gauge reading at pressure tap (3) is within specification. Refer to Table 1 or Table 2.

5. Slowly move the swing control lever for a full left swing operation and check the pressure for relief valve (33) at pressure tap (3).

6. Return the swing control lever to the NEUTRAL position.

7. Loosen locknut (32) on the right swing motor (7). Turn adjustment plug (31) until pressure gauge reading at pressure tap (3) is within specification. Refer to Table 1 or Table 2.

8. Tighten locknut (29) and locknut (32) to a torque of 118 ± 10 N·m (87 ± 7 lb ft).

Note: Turning adjustment plugs (30) and (31) clockwise increases the pressure. Turning adjustment plugs (30) and (31) counterclockwise decreases the pressure.

Note: Always make final pressure adjustment on the pressure rise.

Left Swing Motor

Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.

Note: After the adjustment of the right swing motor is complete, an adjustment of the relief valve pressures for the left swing motor is required to see the relief valve pressures of the left swing motor.

1. Loosen locknut (16) and (19) on the left swing motor (6). Turn adjustment plug (17) and (18) by one half turn counterclockwise.

2. Slowly move the swing control lever for a full right swing operation and check the pressure for relief valve (20) at pressure tap (3).

3. Return the swing control lever to the NEUTRAL position.

4. Loosen locknut (19) on the left swing motor (6). Turn adjustment plug (18) until the pressure gauge reading at pressure tap (3) is within specification. Refer to Table 1 or Table 2.

5. Slowly move the swing control lever for a full left swing operation and check the pressure for relief valve (15) at pressure tap (3).

6. Return the swing control lever to the NEUTRAL position.

7. Loosen locknut (16) on the right swing motor (7). Turn adjustment plug (17) until pressure gauge reading at pressure tap (3) is within specification. Refer to Table 1 or Table 2.

8. Tighten locknut (16) and locknut (19) to a torque of 118 ± 10 N·m (87 ± 7 lb ft).

Note: Turning adjustment plugs (17) and (18) clockwise increases the pressure. Turning adjustment plugs (17) and (18) counterclockwise decreases the pressure.

Note: Always make final pressure adjustment on the pressure rise.