330C Excavator Hydraulic System Caterpillar

Use the procedures that follow in order to check the vertical movement and the circular movement of the swing bearing. Two dial indicators with magnetic bases are required for the procedures.

Procedure To Measure Vertical Movement Of The Swing Bearing

1. Place the machine on level ground.

2. Empty the bucket.

3. Position the upper structure parallel with the tracks.

4. Inspect the static torque of the bolts in the swing bearing in order to make sure that the bolts are tightened properly.

   1. Set the torque wrench to a torque value of 800 N·m (590 lb ft).

   2. Make a mark on the head of the bolt that is relative to the carbody or the bearing race.

   3. Apply the specified torque to the bolt.

   4. If the head of the bolt does not move, the torque is within the specification.

   5. If the head of the bolt moves, replace the bolt.

Show/hide table



Illustration 1	g01107785
(A) Dial indicator (B) Dial indicator (C) Outer race of the swing bearing (D) Inner race of the swing bearing (F) Carbody

5. Refer to Illustration 1. Position dial indicator (A) between the carbody and the outer race of the swing bearing (C) . Position dial indicator (B) between the carbody and the outer race of the swing bearing (C) .

   Note: Position the dial indicators at the front center of the carbody and at the rear center of the carbody.

Show/hide table



Illustration 2	g01107903

6. Refer to Illustration 2 and move the boom, the stick, and the bucket into the position that is shown.

7. Adjust both dial indicators to "zero".

Show/hide table



Illustration 3	g01108255

8. Refer to Illustration 3 for the correct position of the boom, of the stick, and of the bucket. Lower the boom until the front of the machine rises from the ground. The angle between the ground and the track should be approximately 15 degrees.

9. Record the dial indicator readings.

10. Calculate the difference between the values that were recorded in Step 9. If the difference is greater than ± 0.05 mm (± 0.002 inch), additional measurements are necessary. Repeat Step 6 through 9.

11. Remove the dial indicators. Rotate the upper structure three times in a clockwise direction. Rotate the upper structure three times in a counterclockwise direction.

12. Repeat Step 5 through 11 three times. Determine the average value of the three readings. Reference Table 1 for the service limit specifications.

Table 1

Specifications For Vertical Movement
New	Service Limit
1.5 mm (0.06 inch)	3.0 mm (0.2 inch)

Procedure To Measure Circular Movement Of The Swing Bearing

1. Place the machine on level ground.

2. Empty the bucket.

Show/hide table



Illustration 4	g00740359
(E) 1000 mm (39.4 inch)

3. Position the upper structure parallel to the tracks. Refer to Illustration 4 for the correct position of the boom, of the stick, and of the bucket.

4. Stop the engine.

Show/hide table



Illustration 5	g00740365
(A) Dial indicator (C) Outer race of swing bearing (D) Inner race of swing bearing (F) Magnet

5. Position dial indicator (A) on the outer race of swing bearing (C) . Position a magnet (F) on the inner race of swing bearing (D) . The value for the measurement will be the average of four readings.

6. By hand, push the side of the bucket in order to rotate the upper structure in a counterclockwise direction as far as possible. Hold the upper structure in that position while the dial indicator is set to "zero".

7. By hand, push the side of the bucket in order to rotate the upper structure in a clockwise direction as far as possible. Record the dial indicator reading.

8. Remove the dial indicator. Rotate the upper structure three times in a clockwise direction. Rotate the upper structure three times in a counterclockwise direction.

9. Perform Step 5 through 8 for each machine position that is shown in Illustration 6. The evaluation of the movement of the bearing is based on the average value of the four measurements at the four positions that are shown in Illustration 6.

If the measurements for the circular movement of the swing bearing exceed the specifications that are listed in Table 2, check the following components for improper function, wear and/or failure:

• swing gear teeth

• pinion gear in the swing drive

• swing drive

• swing motor

• swing brake valve

• swing control valve

Table 2

specifications for Circular Movement
New	Service Limit
4.5 mm (0.18 inch)	13.5 mm (0.53 inch)

Illustration 6	g00741029