LeeBoy 8520C - Component Replacement Procedures; Gear Pumps Replacement Procedure

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LeeBoy 8520C Conveyor Paver 5-33
Maintenance
Replacement Procedures
Gear PumpsGear Pumps
Hydraulic uid is transmitted throughout the machine to
motors and cylinders, becoming pressurized accord-
ing to the resistance present. The uid is controlled by
valves and distributed through hoses and tubes. Three
gear pumps play a signicant role in producing hydraulic
power as it supplies hydraulic uid to system compo-
nents: The tandem gear, tandem drive, and tandem
auxiliary gear pumps. (Figure 5-39)
The tandem gear and tandem drive pumps are
accessed via the left access panel. The tandem gear
pump is attached to the tandem drive pump (just behind
it). Both are easily reached via the right access panel.
The tandem auxiliary gear pump is easier to access
from the front access panel inside the hopper.
Tandem
Gear Pump
Tandem
Drive Pump
Tandem
Auxilliary
Gear Pump
Figure 5-39. Gear Pumps
Use the following procedure for replacing either of the
gear pumps:
1. Access the gear pump slated for replacement.
2. Label and disconnect the hoses to the gear pump,
capping the tting on the pump.
3. Label, plug and cap the hoses.
The gear pump assemblies are very
heavy and must be properly supported with a sling
before continuing the following steps. DO NOT
loosen mounting bolts unless the pump is sufciently
supported.
4. Remove the two screws on the pump mount (one on
each side of mount). (Figure 5-40)
Tandem Pump
Bolts (2)
Drive Pump
Bolts (2)
Figure 5-40. Hydraulic Pump Assemblies
5. Using a sling, carefully lift the pump assembly out of
the machine and place on a at surface.
6. Remove and inspect the O-ring(s) on end of the
pump for wear or damage. Replace if needed.
7. Put a small amount of hydraulic oil onto the O-Ring
and reinstall.
8. Align the 2 mounting holes with the mounting on the
pump.
9. Reattach with the two mounting screws and torque
(Refer to Torque Tables in Section 2.)
10. Remove plug caps and reconnect hydraulic hoses
to pump as previously labeled.
11. Check hydraulic oil level. Add more if needed.
12. Start the paver and check to be sure there are no
hydraulic oil leaks.
13. Let machine idle approximately 10 minutes to allow
the pump and motor cases to ll with hydraulic oil.