308C CR Excavator Hydraulic System – Cylinder Drift – Check – Empty Bucket

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 g00298378

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

Boom Cylinder Head End, Stick Cylinder Rod End, and Bucket Cylinder Head End

  1. Fully extend the bucket cylinder.
  1. Fully retract the stick cylinder.
  1. Extend the stick cylinder rod 70 mm (2.8 inch) from the fully retracted position.

    Illustration 2 g01402004

  1. Raise the boom until the stick to bucket pin is the same height as the boom foot pin. Refer to Illustration 2.
  1. Measure each cylinder’s length from cylinder pin to cylinder pin.
  1. Stop the engine.
  1. Leave the machine in this position for five minutes. Measure each cylinder’s length from cylinder pin to cylinder pin for drift.

    Table 2
    Cylinder Drift (Empty Bucket)    
    Item     New     Rebuild     Service Limit    
    Boom Cylinder     6.0 mm (0.24 inch) or less     12.0 mm (0.47 inch) or less     24.0 mm (0.94 inch) or less    
    Stick Cylinder     10.0 mm (0.39 inch) or less     15.0 mm (0.59 inch) or less     25.0 mm (0.98 inch) or less    
    Bucket Cylinder     10.0 mm (0.39 inch) or less     15.0 mm (0.59 inch) or less     25.0 mm (0.98 inch) or less    

Stick Cylinder Head End

  1. Start the engine.
  1. Fully extend the bucket cylinder.
  1. Fully extend the stick cylinder.
  1. Retract the stick cylinder rod 60 mm (2.4 inch) from the fully extended position.

    Illustration 3 g01401745

  1. Raise the boom until the stick to bucket pin is 600.0 mm (23.6 inch) high from ground level. Refer to Illustration 3.
  1. Measure the stick cylinder’s length from cylinder pin to cylinder pin.
  1. Stop the engine.
  1. Leave the machine in this position for five minutes. Measure the stick cylinder’s length from cylinder pin to cylinder pin for drift.

    Table 3
    Cylinder Drift (Empty Bucket)    
    Item     New     Rebuild     Service Limit    
    Stick Cylinder     25.0 mm (0.98 inch) or less     30.0 mm (1.18 inch) or less     40.0 mm (1.57 inch) or less    

Bucket Cylinder Rod End

  1. Start the engine.
  1. Fully retract the bucket cylinder.
  1. Fully retract the stick cylinder.

    Illustration 4 g01401747

  1. Raise the boom until the stick to bucket pin is 600.0 mm ( 23.6 inch) high from ground level. Refer to Illustration 4.
  1. Measure the bucket cylinder’s length from cylinder pin to cylinder pin.
  1. Stop the engine.
  1. Leave the machine in this position for five minutes. Measure the bucket cylinder’s length from cylinder pin to cylinder pin for drift.

    Table 4
    Cylinder Drift (Empty Bucket)    
    Item     New     Rebuild     Service Limit    
    Bucket Cylinder     20.0 mm (0.79 inch) or less     25.0 mm (0.98 inch) or less     35.0 mm (1.38 inch) or less