CHECKS
Does the system pressurize to 207 bar (3,002 psi) when moving the mast switch to the raise position?
PROBLEM 23
The mast cylinders will not raise or lower.
POSSIBLE CAUSES
Faulty control valve section, low pump pressure, bad pump, switch failure, faulty
counterbalance valve.
Yes
No
Repair the
problem.
Are mechanical problems present at
the mast assist cylinders?
Yes No
When moving the mast switch, does the accessory system
pressure increase?
Yes No
Adjust the cylinder counterbalance
valve (See Section 2 - Adjusting
Counterbalance Valve.) Does the
cylinder operate correctly?
Replace the cylinder.
No
Check for 28 volts at the mast power switch. (See
Section 3 -Checking Electrical Inputs/Outputs.)
Voltage
No Voltage
Are the solenoids magnetized when
the switch position is enabled?
Yes
No
Replace the power switch.
Replace the solenoid valve.
Check the system pressure for 207 bar (3,002 psi).
Pressure Ok
Pressure not Ok
Repair or replace
the control valve.
Check the accessory/MAX-ER pump pressure output.
Repair or replace the pump, if necessary.
Consult your Manitowoc dealer
or the Crane Care Lattice Team.
To Next Page
Loading...
