2001/12/03 Caterpillar

Motor Grader:

120G (S/N: 11W1251-UP; 1LK630-UP; 4HD1-UP; 61W591-UP; 87V8360-UP)

12G (S/N: 3WC1067-UP; 61M12027-UP)

130G (S/N: 12W1082-UP; 74V2321-UP)

140G (S/N: 13W741-UP; 50H1261-UP; 5MD1-UP; 72V1034-UP)

160G (S/N: 4JD1-UP)

Reference: Service Magazine, SEBD1862, 18 April 1988, "Modification to Make the Snow Wing and/or Blade Side Shift Move Faster"

Reference: Service Magazine, SEBD1885, 26 September 1988, "New Circle Drive Pinions Have Longer Service Life"

With the introduction of the hydraulic system for load sensing, the sound of the engine and resistance of oil flow may indicate that the hydraulic circuit for the circle drive is not functioning efficiently. Modifications to 8W-2284 Motor Lines or 8W-2330 Motor Lines and 9T-1869 Control Valve will improve the hydraulic circuit for the circle drive.

Procedure to Install New Components on 8W-2284 Motor Lines

The following table lists the parts that are required to modify 8W-2284 Motor Lines for the following Motor Graders: 12G, 130G, 140G and 160G.

Illustration 1	g00832783

1. Remove one 8W-4477 Hose As (5) and one 8W-2557 Hose As (6) between the valve bank (A) and 8J-5913 Check Valve (13). Discard the hoses and seals.

2. Remove two existing 6V-9876 Elbows (1) from valve bank (A). Discard the seals.

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Illustration 2	g00832798

3. Remove four existing 6V-8634 Connectors (11) and seals from 8J-5913 Check Valve (13). Discard the seals.

   Note: Ensure that there are no 8J-9979 Chokes (B) in the ports (C) of 8J-5913 Check Valve (13) .

4. Install four new 6V-8638 Seal Connectors (11), four new 3K-0360 O-Ring Seals (2) and four new 6V-8398 O-Ring Seals (3) in 8J-5913 Check Valve (13) .

5. Install two new 6V-9002 Elbows (1), two new 3K-0360 O-Ring Seals (2) and two new 6V-8398 O-Ring Seals (3) in valve bank (A) .

6. Assemble one 6V-9965 Coupling (4), one 165-0017 Hose (6) and one 6V-9967 Coupling (12). This hose assembly replaces the existing 8W-2557 Hose Assembly (6) .

7. Install one 6V-9965 Coupling (4) into one 6V-9002 Elbow (1). Install one 6V-9967 Coupling (12) into 6V-8638 Seal Connector (11) .

8. Assemble one 6V-9965 Coupling (4), one 165-0017 Hose (5) and one 6V-9967 Coupling (12). This hose assembly replaces the existing 8W-4477 Hose Assembly (6) .

9. Install one 6V-9965 Coupling (4) into one 6V-9002 Elbow (1). Install one 6V-9967 Coupling (12) into 6V-8638 Seal Connector (11) .

10. Remove two existing 8W-0214 Hoses (10) between the circle drive motor and 8J-5913 Check Valve (13) .

11. Remove two existing 6V-8715 Connectors (7) and seals from the circle drive motor. Discard the seals.

12. Install two 6V-8639 Connectors (7) and two new 2M-9780 O-Ring Seals (8) in the circle drive motor.

13. Assemble two 6V-9966 Couplings (9), two 165-0017 Hoses (10) and two 6V-9965 Couplings (4). These two hose assemblies replace the existing two 8W-0214 Hose Assemblies (10) .

14. Install two 6V-9966 Couplings (9) to two 6V-8639 Connectors (7). Install two 6V-9965 Couplings (4) into two 6V-8638 Seal Connectors (11) .

15. Enlarge holes in existing 2G-2562 Clamp (14) in order to accept 165-0017 Hose. The outside diameter of the hose is 24 mm (1 inch).

    Note: For maximum performance, set system pressure to 24000 +350-0 kPa (3480 +51-0 psi).

Procedure to Install New Components on 8W-2330 Motor Lines

The following table lists the parts that are required to modify 8W-2330 Motor Lines for the 120G Motor Grader.

Illustration 3	g00834310

1. Remove two 8W-3065 Hose Assembly (5) between valve bank (A) and 8J-5913 Check Valve (12). Discard the hose assemblies and the seals.

2. Remove two existing 6V-9876 Elbows (1) and seals from valve bank (A). Discard the seals.

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Illustration 4	g00832798

3. Remove four existing 6V-8634 Connectors (7) and seals from 8J-5913 Check Valve (12). Discard the seals.

   Note: Ensure that there are no 8J-9979 Chokes (B) in the ports (C) of 8J-5913 Check Valve (12) .

4. Install four 6V-8638 Seal Connectors (7), four 3K-0360 O-Ring Seals (2) and four 6V-8398 O-Ring Seals (3) in 8J-5913 Check Valve (12) .

5. Install two new 6V-9002 Elbows (1), two new 6V-8398 O-Ring Seals and two new 3K-0360 O-Ring Seals (2) into valve bank (A) .

6. Assemble two 6V-9965 Couplings (4), two 165-0017 Hoses (5) and two 6V-9967 Couplings (6). These assemblies replace the two existing 8W-3065 Hose Assemblies (5) .

7. Install two 6V-9965 Couplings (4) into two 6V-9002 Elbows (1). Install two 6V-9967 Couplings (6) into two 6V-8638 Seal Connectors (7) .

8. Remove two existing 8W-0214 Hoses (11) between the circle drive motor and 8J-5913 Check Valve (12) .

9. Remove two 6V-8715 Connectors (8) and seals from the circle drive motor. Discard the seals.

10. Install two new 6V-8639 Connectors (8) and two new 2M-9780 O-Ring Seals (9) to the circle drive motor.

11. Assemble two new 6V-9966 Couplings (10), two 165-0017 Hoses (11) and two new 6V-9965 Couplings (4). These hose assemblies replace two 8W-0214 Hoses (11) .

12. Install two 6V-9966 Couplings (10) into two 6V-8639 Connectors (8). Install two 6V-9965 Couplings (4) into two 6V-8638 Seal Connectors (7) .

13. Enlarge holes in existing 2G-2562 Clamp (13) in order to accept 165-0017 Hose. The outside diameter of the hose is 24 mm (1 inch).

    Note: For maximum performance, set system pressure to 24000 +350-0 kPa (3480 +51-0 psi).

The Procedure for the Installation of New Components and the Modification of 9T-1869 Control Valve

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Illustration 5	g00832987

1. Remove the following parts from the valve body: 9T-3002 Plug (1) , 4K-1388 O-Ring Seal (2), 9T-2570 Spring (3) and three 9M-1974 Hard Washers (4). Discard the seal and the spring.

2. Remove 9S-8009 O-Ring Plug (6), 4K-1388 O-Ring Seal (2) and valve (5). Discard the seal.

3. Measure the diameter of the two holes in location (A). The diameter of the two holes in location (A) must be 6.76 mm (0.266 inch). If necessary, enlarge the holes.

   Reference: Service Magazine, SEPD, 18 April 1988, "Modification to Make the Snow Wing and/or Blade Side Shift Move Faster"

4. Install one 9M-1974 Hard Washer (4), one 4K-1388 O-Ring Seal (2) and one 9S-8009 O-Ring Plug .

5. Install valve (5), one new 4K-1388 O-Ring Seal (2) and 9S-8009 O-Ring Plug (6) .

6. Install the following parts: one 9M-1974 Hard Washer (4), one new 8J-1630 Spring (3), one new 4K-1388 O-Ring Seal (2) and one 9T-3002 Plug (1).

   Reference: Service Magazine, SEBD1885, 26 September 1988, "New Circle Drive Pinions Have Longer Service Life"

   Note: There may be situations when the operator is using multiple circuits with the circle drive. The change of the flow may decrease the total number of circuits that can be effectively used. If this is a problem, further modifications can be made to the flow control valve. Contact Service Engineering for assistance.