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

Removal Procedure

Start By:

1. Connect the steering frame lock.

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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.

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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.

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

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Illustration 1	g02731334

2. 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.

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Illustration 2	g01415039

3. Disconnect hose assemblies (1). Remove clamp (2) .

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Illustration 3	g01415042

4. Remove bolts (6) and remove cap (7) .

   Note: Note the shims and inserts for installation purposes.

5. Attach a suitable lifting device to blade lift cylinder (5). The weight of blade lift cylinder (5) is approximately 59 kg (130 lb).

6. Remove bolts (3) and remove blade lift cylinder (5) .

7. Remove cap assemblies (4) from blade lift cylinder (5) .

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Illustration 4	g01415199

8. Remove seal (8) from cap assembly (4). Remove bearing (9) from cap assembly (4) .

9. Repeat Step 8 for the remaining cap assembly.

Disassembly and Assembly Information

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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 5	g00931771

(1) Use a 46 mm socket in order to remove the bolt. Tighten the bolt to a torque of 1800 ± 200 N·m (1328 ± 148 lb ft).

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

(3) Apply Tooling (D) to the seal groove prior to assembling the wiper seal.

(4) Torque for head ... 600 ± 130 N·m (440 ± 95 lb ft)

Note: Lubricate the threads with Tooling (E) .

Installation Procedure

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Illustration 6	g01415199

1. Use Tooling (H) (not shown) and a suitable press in order to install bearing (9) in cap assembly (4). Use Tooling (H) (not shown) in order to install seal (8) in cap assembly (4).

2. Repeat Step 1 for the remaining cap assembly.

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Illustration 7	g01415042

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Illustration 8	g01415219

3. Install caps (4) on blade lift cylinder (5) .

4. Attach a suitable lifting device to blade lift cylinder (5). The weight of blade lift cylinder (5) is approximately 59 kg (130 lb).

5. Position blade lift cylinder (5) on the machine. Install bolts (3). Torque bolts (3) to 115 ± 7 N·m (85 ± 5 lb ft).

6. Apply Tooling (G) between inserts (11) and ballstuds (12). Install cap (7) and install bolts (6).

   Note: As required, use shims (10) in order to allow the socket to move freely around ballstud (12). Assemble the same quantity of shims (10) on both sides of ballstud (12) .

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Illustration 9	g01415039

7. Install clamp (2). Connect hose assemblies (1).

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Illustration 10	g02731334

8. Remove Tooling (A) .

9. Refer to Operation and Maintenance Manual, "Hydraulic System Oil Level - Check" for the correct procedure.