Labrie Pendpac WITTKE RETRO FL, Maintenance Manual

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98
Maintenance
Š
Working Sections
Hopper top door, tailgate, arms, forks and pack circuits are controlled by a work section dedicated
to each function. Air actuators attached to the work section shift the spool in the desired direction
to allow pressurized oil to operate the hydraulic cylinder. Returning oil is allowed to escape to tank
via the return passage, outlet section & return lines.
Š
Outlet Section
Caps the bottom of the valve bank to provide a path for returning oil to travel to the return line
filter in the tank.
Figure 3-37 Directional control valves
Pressure Relief Valve
The pressure relief valve is fitted in the inlet section of the valve bank and protects the hydraulic
components from damage caused by loads in excess of 2250 psi. When pressure exceeds the setting of
the relief valve, the oil overcomes the adjustment spring and opens the relief valve allowing oil to
return to the tank.
Figure 3-38 Pressure relief valve
Work Circuits (Commercial)
The circuits have been listed from top to bottom as they appear in the valve bank assembly
(see Figure 3-37).
N
OTE
:
The following list is for the commercial front loader only. See following sections for residential
and tip-to-dump configurations.