Manitowoc 18000, Service Maintenance Manual, Page: 84 / 316

Reference
Only
INTRODUCTION 18000 SERIVCE/MAINTENANCE MANUAL
1-72
Published 12-05-17, Control # 035-23
Mast Pins
See Figures 1-39 and 1-43 for the following procedure.
During normal operation the mast pins solenoid valve is
“motor spooled” where both cylinder ports and tank port of
valve spool section are connected in center position.
Power is available to hand-held radio remote control when
setup remote mode is selected, engine is running, and power
button is pressed. The mast pins cannot be engaged/
disengaged until keeper plates from pins are removed.
When mast pins switch is placed in the engage position and
held, an input voltage is sent to node-1 controller. Node-4
controller sends a 24 volt output to enable mast pins
solenoid valve HS-31 and shifts valve to the engage position.
Node-5 controller sends a variable zero to 24 volt output
voltage to enable accessory system proportional relief valve.
When an accessory valve spool shifts, supply flow to the
other accessory valves is limited. The accessory system
pressure sender monitors accessory system pressure.
Hydraulic fluid pressure at approximately 3,000 psi (204 bar)
flows to mast pins accessory valve. Hydraulic fluid leaves the
accessory valve and enters piston end of mast pin cylinders,
extending cylinder rods to engage the mast pins. Hydraulic
fluid from rod end of mast pin cylinders leaves accessory
system valve and returns to tank. When mast pins switch is
released, solenoid valve HS-31 returns to center.
When mast pins switch is placed in disengage position and
held an input voltage is sent to node-1 controller. Node-4
controller sends a 24 volt output to enable mast pins
solenoid valve HS-32 and shifts valve to disengage position.
Node-5 controller sends a variable zero to 24 volt output
voltage to enable accessory system proportional relief valve.
Hydraulic fluid pressure at approximately 3,000 psi (204 bar)
flows to mast pins accessory valve. Hydraulic fluid exits
accessory valve and enters rod end of mast pin cylinders,
extending cylinder rods to disengage the mast pins.
Hydraulic fluid from piston end of mast pin cylinders exits
accessory system valve and returns to tank. When mast pins
switch is released, solenoid valve HS-32 returns to center.