CD397-Oper
Operation - 2 - 7
June 2019 (Rev C)
Operation
Mobile Belt Loader Model 660-28
Section 2
Operation Manual
2.2.2.3
Pilot-Operated
Hydraulic
Check
Valves
The pilot-operated hydraulic check valves are located on both lift cylinders and the reverse travel direction
of the conveyor belt motor. The conveyor belt motor counted-balance valve prevents the free wheeling of
the conveyor belt if the belt is stopped with the conveyor at an incline. The check valves prevent the
cylinders from lowering unless pressurized.
2.3
Procedures
2.3.1
Pre-Operation
Checklist
Procedures for pre-operation checks before maneuvering the vehicle to an aircraft shall include (but may
not be limited to) the following items:
1. Fuel Level
2. Tire Inflation
3. Engine Oil Level
4. Transmission Oil Level
5. Seatbelt Serviceability
6. Service Brake Effectiveness
7. Park Brake Effectiveness
8. Vehicle Drive Forward
9. Vehicle Drive Reverse
10. Check the hydraulic fluid level with the conveyor down
11. Conveyor Belt Drive in Forward direction
12. Conveyor Belt Drive in Reverse direction
13. Front Cylinder Extension: Raises front of conveyor
14. Front Cylinder Retraction: Lowers front of conveyor
15. Rear Cylinder Extension: Raises back of conveyor
16. Rear Cylinder Retraction: Lowers back of conveyor
17. Verify all “E” Stops function correctly
18. Check that oil does not have a milky appearance
19. Check for condensation under the oil fill cap
NOTE:
Milky oil is a sign of water in the oil, and the tractor should be turned over for service imme-
diately.
Property
of
American
Airlines