120M Series 2 and 120M2 Motor Graders Machine Systems Caterpillar

Removal Procedure

Start By:

1. Connect the steering frame lock.

Show/hide table

Hydraulic oil pressure can remain in the hydraulic system on this machine after the engine and pump have been stopped. Serious injury can result if this pressure is not released before any service is done on the hydraulic systems. In order to prevent possible injury, release the hydraulic system pressure before working on any fitting, hose, or hydraulic component. Lower all attachments to the ground before service is started. If the hydraulic system must be serviced, tested, or adjusted with the attachment in the raised position, the attachments and lift cylinders must be supported properly. Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.

Show/hide table

When you are using hydraulic cylinders and puller studs, always ensure that the rated capacity of the puller stud meets or exceeds the rated capacity of the hydraulic cylinder. If the puller stud does not meet or exceed the rated capacity of the hydraulic cylinder, a sudden failure of the puller stud could occur. The sudden failure of the puller stud could result in personal injury or death.

1. Connect the steering frame lock.

2. Refer to Operation and Maintenance Manual, "Battery Disconnect Switch".

3. Refer to Operation and Maintenance Manual, "System Pressure - Release".

Show/hide table



Illustration 1	g02731334

4. Install Tooling (A) onto the hydraulic tank. Attach an air supply hose onto Tooling (A). Apply 138 kPa (20 psi). This procedure will pull a vacuum on the hydraulic system.

Show/hide table



Illustration 2	g02731554

5. Remove panel (1) on the left side.

Show/hide table



Illustration 3	g02731551

6. Disconnect hose assemblies (2) and harness assemblies (3). Remove bolts (4) and position bracket (5) out of the way.

Show/hide table



Illustration 4	g02731563

Show/hide table



Illustration 5	g02731568

7. Remove cotter pin (6). Remove bolt (7) and pin assembly (8) .

Show/hide table



Illustration 6	g02731579

8. Remove cotter pin (9) and bolt (10). Disconnect hose assemblies (11). Remove pin assembly (12). Use two people to remove articulation cylinder (13). The weight of articulation cylinder (13) is approximately 34 kg (75 lb).

Show/hide table



Illustration 7	g02731595

9. Remove seal assemblies (14) .

10. Remove pin (5) and remove the washer (not shown).

Show/hide table



Illustration 8	g02731599

11. Use Tooling (B) to remove bearing (15). Repeat the process for the other side.

Disassembly and Assembly Information

Show/hide table

Cylinders equipped with lock valves can remain pressurized for very long periods of time, even with the hoses removed. Failure to relieve pressure before removing a lock valve or disassembling a cylinder can result in personal injury or death. Ensure all pressure is relieved before removing a lock valve or disassembling a cylinder.

Illustration 9	g01401445

(1) Apply Tooling (H) to the threads of bolt (1).

(2) Apply Tooling (J) to wiper seal groove (2) prior to assembly.

(3) Tighten head (3) to a torque of 600 ± 130 N·m (443 ± 96 lb ft).

(4) Lubricate sealing lips with a thin covering of the lubricant that is being sealed.

Installation Procedure

1. Install articulation cylinder (13) in the reverse order of removal.

   1. Use Tooling (D) to install bearing (15) .