CONTROLLER AS 4827737 - Caterpillar

4. Position blade in vertical position at about 8 or 9 on the blade tip indicator.
Do not adjust the circle level on the rear of the circle unless resetting it with respect to circle. Leveling it to the cutting edge will introduce errors in operation. Errors will increase as blade is circled to higher angles.
5. Center leveling bubble, to level circle, by manipulating lift arms. 6. If machine has been used check cutting edge for wear. (See topic Cutting Edge Wear, page 19). 7. With slope control dial at zero, slope meter should read zero. Dial drag can be adjusted with 2 set-screws on the dial. Be sure the dial is in the correct zero location when calibrating the slope control. The slope control dial can be rotated 1 revolution counterclockwise and 2 revolutions clockwise from the zero position. Be sure physical stops are encountered when locating this position. The 2nd revolution in the clockwise direction is not used. 8. If the meter is off to either side, loosen dial thumbscrew. 9. Bring meter back to zero by turning hub with a flat tool, while holding dial at zero. 10. Turn grade and slope selector to the left slope position. 11. Turn slope switch ON. Grade switch should be OFF. 12. Raise left lift arm with manual control. 13. Watch the slope meter and left cylinder. Meter should return to zero when cylinder movement stops. There should be no further movement. 14. If meter needle does not stay within center black band, adjust left servo valve. 15. Remove valve protection cover.Servo Valve Adjustment (Type One)
16. Insert a hex head wrench (1) in the small hole in the valve body. Loosen the setscrew enough to allow bushing pin to turn (not more than 1/8 turn 45°). 17. Insert short, narrow blade screwdriver (2) in the adjusting hole of valve body. Adjust the bushing pin until the slope meter reads zero and cylinder movement stops. 18. Lock setscrew. Make sure setscrew bottoms against bushing. Do not overtighten.Servo Valve Adjustment (Type Two)
16. Loosen the self-locking nut with a 3/8 inch offset box wrench. Do not remove nut. Loosen only enough to allow movement of the null adjuster pin. 17. Insert a 3/32 inch hex head screw wrench in the null adjuster pin and turn until meter is zeroed and cylinder movement stops. 18. To prevent null adjuster pin rotation after null has been obtained, hold the pin with the hex head screw wrench while tightening the lock nut. 19. Turn grade and slope selector to the right slope and repeat steps 11 through 18 for the right side.Servo Valve Filter
Service servo valve filter only when filter change light is on. Replace filter if filter change light is on constantly or blinks continuously after hydraulic oil is warm.Check Cutting Edge Wear
The procedure for checking and calibrating slope control is based on using the circle for level reference, assuming the moldboard is parallel to the circle. Whenever calibrating slope control it may be