308C CR Excavator Hydraulic System – Visual Inspection

A visual inspection of the system is the first step in order to troubleshoot a problem. Shut off the engine and lower all implements to the ground before performing the visual inspection.

  1. Check the oil level in the hydraulic tank. Slowly loosen the fill/vent plug and release the pressure before the fill/vent plug is removed.


    Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.

    Refer to Special Publication, NENG2500, “Caterpillar Tools and Shop Products Guide” for tools and supplies suitable to collect and contain fluids on Caterpillar products.

    Dispose of all fluids according to local regulations and mandates.

  1. Remove the hydraulic filter elements. Inspect the hydraulic filters for material that would give an indication of damage to a component.
  1. Inspect all lines and connections for damage or leaks.
  1. Inspect control linkages for bent components, broken components or damaged components.