Manitowoc 999, Service And Maintenance Manual

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Reference
Only
TROUBLESHOOTING 999 SERVICE/MAINTENANCE MANUAL
10-26
Published 05-16-17, Control # 233-03
Problem 23
Boom hinge pin cylinders will not extend or retract.
CHECKS
Does system pressurize to 3,500 psi when moving boom hinge pins switch
to extend or retract position at remote controller?
POSSIBLE CAUSES
Not in setup mode; Faulty control valve section; Low pump pressure; Bad
pump; Switch failure; Mechanical problem.
Yes No
Are mechanical problems present at
boom hinge pin cylinders?
Yes No
See Diagnostic Display topic in section 3. Does (bank 5) change
by 4 for extend and by 8 for retract, when moving boom hinge pin
switch to extend or retract position?
Voltage No Voltage
Yes No
Is crane setup mode
selected and confirmed?
Yes No
Consult dealer/
factory. Select and confirm
setup mode.
Check for 12 volts at boom hinge pin switch, pin number WB-31 for extend or WB-32 for retract.
Replace cylinder or
consult dealer/factory. Repair problem.
Are solenoids magnetized when switch
position is enabled?
Yes No
Replace power switch fuse F4.
Replace solenoid valve.
Check diagnostic display DRUM 2 screen (bank 6)
for 350 psi charge pressure with handle in neutral.
Pressure Ok Pressure not Ok
Repair or replace
control valve. Adjust rear drum charge pressure. (See Test 17.)
Repair or replace rear drum pump, if necessary.