330,330 L & 330 LN EXCAVATORS MACHINE SYSTEMS Caterpillar

NOTE: The shock reducing valve is mounted to the main frame, next to the swing drive.

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At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns. To prevent possible personal injury, release the pressure in the implement hydraulic circuits (boom, stick and bucket) before any hydraulic lines or components are disconnected or removed.

1. Release the pressure in the hydraulic system as follows:

a. Fully retract the rod in the stick cylinder.

b. Adjust the position of the bucket so it will be flat on the ground when the boom is lowered.

c. Lower the boom until the bucket is flat on the ground.

d. Shut off the engine, and put the hydraulic activation control lever in the "Lock" position.

e. Move the control levers for the boom, bucket, stick and swing through their full travel strokes. This will relieve any pressure that may be present in the pilot system.

f. Slowly loosen the air breather cap on the hydraulic oil tank to release the pressure.

g. Tighten the air breather cap on the hydraulic oil tank.

h. The pressure in the hydraulic system has now been released. Lines and components can now be removed.

2. Put identification marks on the six hose assemblies that are connected to the shock reducing valve. Disconnect six hose assemblies (1) from the shock reducing valve.

3. Remove four bolts (2) that hold the shock reducing valve in place. Remove shock reducing valve (3).

NOTE: Install the shock reducing valve in the reverse order of removal.

4. Check the oil level in the hydraulic oil tank. Fill the hydraulic oil tank with oil to the correct level. See the Operation & Maintenance Manual for the correct filling procedure.

Disassemble & Assemble Shock Reducing Valve

Start By:

a. remove shock reducing valve

1. Be sure the outside of the shock reducing valve is thoroughly clean prior to disassembly.

2. Remove plugs (1) and (7) from the valve body.

3. Remove O-ring seal (2) from plug (1) and O-ring seal (6) from plug (7).

4. Remove two springs (3) and (5) and valve (4) from the valve body.

NOTE: The following steps are for the assembly of the shock reducing valve.

5. Be sure all parts of the shock reducing valve are thoroughly clean prior to assembly.

6. Check the condition of all O-ring seals used in the shock reducing valve. If any of the seals are worn or damaged, use new parts for replacement.

7. Assemble the shock reducing valve in the reverse order of disassembly.

End By:

a. install shock reducing valve