NO. 112, 120 & 140 MOTOR GRADERS Every 1000 Service Hours Or 6 Months Caterpillar

(38)Hydraulic Control System - Change Oil and Filter Element

1. Park machine, lower blade and raise hydraulic controlled implements. Remove filler cap.

2. Remove drain hole cover and allow to drain.

3. Remove filter drain plug and allow to drain.

4. Lower raised implements. Remove filter base bolts.

5. Remove filter base, spring, seat and element.

6. Inspect filter base and plug seals. Replace if necessary. Clean housing.

7. Install base, spring, seat and new element.

8. Clean and install filter drain plug.

9. Clean and install drain cover.

10. Fill tank to top of filler neck. (Refill capacity on page 44.)

11. Put filler cap on finger tight. Start engine. Raise hydraulic controlled implements.

12. Remove filler cap and fill tank to top of filler neck. Put cap on loosely.

13. Open hydraulic cylinder vent valves, if so equipped. Raise and lower implement until oil flows free of bubbles out of vent valves.

14. Close vent valves and check oil level. Put filler cap on finger tight.

15. Purge air from system. Work all hydraulic implements through a complete cycle a few times.

16. Stop engine and check oil level.

17. Fill to top of filler neck. Install cap tightly.

18. Check hydraulic oil level after a few hours of operation. Add oil as required.

(39)Blade Lift

One housing on each side. Maintain level to bottom of level plug opening. Filler opening is at top.

(40)Center Shift Housing

1. Check oil level at filler opening.

2. Maintain level to bottom of filler opening.

(41)Front Wheel Bearings

Lubricate 1 fitting each front wheel. Total 2 fittings.

(42)Flywheel Clutch Compartment Screen - Wash

1. Turn drain plug counterclockwise to drain compartment.

2. Remove cover, screen and gasket. Wash and inspect screen.

3. Install screen gasket, housing and close drain. (Use new screen and/or gasket if necessary.) Check oil level.

(43)Circle Center Shift Pinion - Check Adjustment

Check backlash of pinion with rack centered, rack run full right and full left. Backlash at any point should be .010 to .030 inch (0,30 to 0,76 mm). See your AVSpare dealer for adjustment procedure.

(44)Blade Circle - Check Adjustment

1. Center and level blade 3 to 4 inches (75 to 90 mm) off ground. Check clearance between each wear plate and top of circle.

2. Clearance should be .010 to .062 inch (0,30 to 1,57 mm). Rotate blade 360°. Stop every 90° and check.

3. Remove shoe bolts and remove or add shims to adjust clearance. Use new shoes if adjustment cannot be made.

4. Install shims and bolts. Check clearance as given in step 2.

5. Lower blade to the ground and inch machine forward to put a light load on front shoes.

6. Measure distance between O.D. of pinion and machined I.D. of circle. Measurement should be 1.90 to 1.92 inch (48,2 to 48,8 mm).

7. If distance is less than 1.90 inch (48,2 mm) replace front shoes and do steps 1 thru 4. 8. Loosen locknuts or rear shoe adjusting screws.

9. Turn adjusting screws to move toe of each rear shoe against circle. (If shoes cannot be made to contact circle, install new shoes and perform steps 1 through 4.) Back adjusting screws out 1/3 turn and lock screws.

10. Check clearance between rear shoes and I.D. of circle. With light load on front shoes, clearance should be .030 to .090 inch (0,76 to 2,29 mm). If not, adjust shoes in or out, as necessary, with adjusting screws.

11. Rotate circle a complete revolution to make sure it moves freely.