308C CR Excavator Hydraulic System – Boom Cylinder – Remove

Removal Procedure

Start By:

  1. Release the hydraulic pressure. Refer to Disassembly and Assembly, “Hydraulic Pressure – Release”.

------ WARNING! ------

Personal injury can result from hydraulic oil pressure and hot oil.

Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.

Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.



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.


Keep all parts clean from contaminants.

Contamination of the hydraulic system with foreign material will reduce the service life of the hydraulic system components.

To prevent contaminants from entering the hydraulic system, always plug or cap the lines, fittings, or hoses as they are disconnected. Cover any disassembled components and clean them properly before assembly.

Clean the hydraulic system properly after any major component exchange or especially after a component failure, to remove any contamination.

Note: Put identification marks on all hose assemblies and on all tube assemblies for installation purposes. Plug all hose assemblies and all tube assemblies. This helps to keep contaminants from entering the system.

    Illustration 1 g00915780

  1. Disconnect hose assemblies (1) .
  1. Remove cover (2) .
  1. Attach a suitable lifting device to the boom cylinder.

    Illustration 2 g00915781

  1. Remove bolt (3).
  1. Remove pin assembly (4) .

    Illustration 3 g00915802

  1. Remove bolt (5) .
  1. Remove pin (6) .