Hoist Control Valve (H0-15 Hoist)
The hoist control valve is designed to provide an
operated poppet off its seat. This allows flow to the
even flow of oil to the hoist motor in both directions.
return reservoir through the directional control valve.
To drive the hoist motor in the raise direction,
An orifice plug is installed in the pilot pressure port to
hydraulic oil flows through the in port and pushes the
restrict back flow when the directional control valve is
free flow poppet off its seat. The oil then flows to the
closed. The restriction prevents the pilot-operated
out port and on to the hoist drive motor.
poppet from chattering on its seat.
When driving the hoist motor in the lower direction,
A vent is provided that vents the area between the
oil from the directional control valve enters the out
pilot piston seal and the free flow poppet and pilot-
port. The pilot-operated poppet is held shut by the
operated poppet seals to prevent a hydraulic lock
adjustment spring until pilot pressure of sufficient
should weepage around the seals occur.
force is sensed at the pilot pressure port to move the
Connect the hydraulic lines to the valve as
tagged during removal.
Tag and disconnect the hydraulic lines running
With the engine running at governed rpm, activate
Remove the bolts and washers securing the
the hoist several turns in both directions. Check for
proper operation and check the valve for any
Position the valve and secure in place with the