650 & 660 TRACTOR-SCRAPER Every 2000 Service Hours Caterpillar

Every 2000 Service Hours
1.1. (40)Hydraulic System - Change Oil and Wash Filler Strainer
2.1. (41)Tachometer Drive Cable - Repack
3.1. (42)Engine Valve Lash - Check - Adjust

(40)Hydraulic System - Change Oil and Wash Filler Strainer

1. Drive machine over a ditch so bowl cylinders will move a complete stroke. Raise the bowl and apron and move the ejector back. When oil is warm, stop the engine.

2. Remove filler cap slowly to relieve pressure.

3. Remove tank drain plug.

4. Turn drain valve and drain oil.
5. Lower bowl and apron complete stroke of cylinders. Do not use QUICK DROP or FLOAT positions.
6. Change filter elements. (See item 32.)
7. Close drain valve.
8. Clean and install drain plug.

9. Remove snap ring and filler strainer. Wash strainer in kerosene. Install strainer.

10. Fill hydraulic tank to bottom of filler strainer. (Refill capacity on page 31.)

11. Start engine and run at low idle with controls in HOLD position.

12. Fill tank to FULL mark on gauge and install filler cap.

13. Move ejector forward and back 3 or 4 times. With ejector forward, add oil to FULL mark on gauge.

14. Raise and lower apron 3 or 4 times. Do not use FLOAT position. With apron lowered, add oil if necessary.

15. Raise and lower bowl 3 or 4 times. Do not use QUICK DROP position. With bowl down, add oil if necessary.
16. With engine running approximately 1200 RPM, move bowl, apron and ejector through 2 or 3 complete cycles.
17. Move machine to level ground.
18. Bleed filters. (See item 32.)

19. Stop engine and check oil Bring oil level to FULL mark on gauge.

20. Check filler cap gasket. Use new gasket. Install cap.

(41)Tachometer Drive Cable - Repack

1. Disconnect cable assembly from tachometer.

2. Pull out and wipe off cable.

3. Lubricate 3/4 of cable, from drive end, and install in housing. Connect assembly.

(42)Engine Valve Lash - Check - Adjust

Adjust valves with engine stopped.

Valve Lash Setting

2. Remove camshaft covers.

3. Remove inspection cover.

4. Remove pinion and spacer.

5. Install pinion without spacer.

6. Turn pinion to align hole in flywheel housing with hole in flywheel.

7. Install 3 inch (76 mm) bolt (remove in step 3) in flywheel.

The valves for No. 1 or No. 7 cylinder are closed at this point.

If valves for No. 1 cylinder are closed-adjust exhaust valves 1, 4, 5 and 8.

Adjust inlet valves 1, 3, 6 and 8.

If valves for No. 7 cylinder are closed-adjust exhaust valves 2, 3, 6 and 7.

Adjust inlet valves 2, 4, 5 and 7.

8. Turn adjusting screw counterclockwise 2 clicks or more to provide clearance between rocker assembly and valve.
9. Turn adjusting screw clockwise to obtain zero lash. There should be no free rocker movement or adjusting screw button lateral movement.


The adjusting screw button can still be rotated by finger pressure even when it is in contact with valve stem and clearance is zero. Turning the adjusting screw clockwise beyond this point will force the valve off its seat, and final lash setting will be incorrect.

10. Turn screw counterclockwise specified number of clicks on detent (see page 22).

11. Remove bolt and turn flywheel 360°.

12. Install bolt in flywheel. Adjust remaining valves.
13. Remove pinion and install spacer under pinion.
14. Remove bolt from flywheel.
15. Install inspection cover.
16. Install camshaft covers.