330,330 L & 330 LN EXCAVATORS MACHINE SYSTEMS Caterpillar

NOTE: The automatic travel speed change valve is located behind the right rear access door.

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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.

2. 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 four hose assemblies (2) for installation purposes. Disconnect four hose assemblies (2) from the automatic travel speed change valve. Put plugs in the hose assemblies to keep dirt and debris out of the hydraulic system.

3. Remove four bolts (1) and the washers that hold the automatic travel speed change valve in place. Remove automatic travel speed change valve (3).

NOTE: Install the automatic travel speed change 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 Automatic Travel Speed Change Valve

Start By:

a. remove automatic travel speed change valve

1. Be sure the automatic travel speed change valve is thoroughly clean prior to disassembly. Put identification marks on all parts of the automatic travel speed change valve for assembly purposes.

2. Remove four socket head bolts (1) and plates (2) and (3) from the valve body. If necessary, remove the locknut and adjusting screw from plate (2).

3. Install a suitable size bolt in the threaded hole in the end of stopper (4). Pull stopper (4) straight out of the valve body.

4. Remove spring (5) and guide (6) from the valve body. Remove ball (10) from guide (6).

5. Remove O-ring seal (9) from stopper (4).

6. Remove stopper (12) and the spool assembly from the valve body.

7. Remove piston (8) from stopper (12). Remove spool (7) from valve (11).

8. Remove two O-ring seals (14) from stopper (12). Remove ring (13) from valve (11).

NOTE: The following steps are for the assembly of the automatic travel speed change valve.

9. Be sure all parts of the automatic travel speed change valve are thoroughly clean prior to assembly of the valve. Put clean hydraulic oil on all internal parts. Check the condition of all O-ring seals and rings used in the automatic travel speed change valve. If any of the seals or rings are worn or damaged, use new parts for replacement.

10. Install two O-ring seals (14) on stopper (12).

11. Install ring (13) on valve (11).

12. Install O-ring seal (9) on stopper (4).

13. Install piston (8) in stopper (12).

14. Install spool (7) in valve (11).

15. Install valve (11) and stopper (12) in the valve body.

16. Install ball (10) in guide (6).

17. Install guide (6), spring (7) and stopper (4) in the valve body.

18. Reinstall plates (2) and (2) and socket head bolts (1) that hold them.

NOTE: If the adjustment screw and locknut in plate (2) was removed, tighten the locknut to a torque of 16 ± 1.6 N·m (12 ± 1.18 lb ft)after adjustment of the automatic travel speed change valve.

End By:

a. install automatic travel speed change valve