Manitowoc 1400A User Manual

National Crane 1-21-2019 Control # 104-07 2-21
1400A SERVICE MANUAL HYDRAULIC SYSTEM
2
Slow response.
Low hydraulic oil level. Fill reservoir.
Hydraulic oil temperature too high (thin oil)
or too low (thick oil).
If the temperature is too high, check the cooler
circuit. If the temperature is too low, warm up
system.
Faulty pump section(s). Repair or replace pump section(s) or entire pump.
Pump noise accompanied
by hydraulic oil foaming in
reservoir.
Low hydraulic oil level Fill reservoir.
Excessive engine speed. Regulate engine speed.
Air entering at suction lines.
Check that all line connections are tight. Tighten,
repair, or replace as needed.
Excessive pressure
buildup.
Circuit relief valve malfunction or set too
high.
Pressure check circuit relief and adjust or replace
relief valve.
Restricted pump-to-control valve supply
line.
Clean, repair, or replace line as necessary.
Specific hydraulic system
(lift, hoist, telescope,
swing) not working.
Leak in system. Repair leak.
Faulty directional control valve. Replace valve.
Troubleshoot circuit with schematic.
Poorly adjusted control in circuit. Adjust hydraulic
component.
Faulty hydraulic cylinder, motor, or valve. Replace faulty component.
No response to control
Crane function power switch off Turn crane function power switch on.
Load too heavy. Check Capacity Chart.
RCL inoperative. Insure RCL is programmed properly and Anti-Two Block/
Overload solenoids are powered.
PTO not engaged. Engage PTO.
Low hydraulic fluid supply. Check and fill as required.
Suction line blocked. Drain tank and hose and remove blockage.
Broken hydraulic pressure line. Replace as required.
Defective hydraulic pump. See Pump Service Manual.
Incorrect relief valve setting. Adjust relief.
Relief valve sticking. Clean relief or replace.
Hydraulic controllers inoperative Check for pilot pressure at main valve bonnets.
Mesh screen in crane manifold clogged
(pilot circuit)
Remove and clean or replace screen.
Poor hydraulic system
performance
Pump not operating at proper speed or
displacement.
Check PTO ratio, pump size and engine speed for
proper oil flow.
Low hydraulic fluid supply. Check and fill as required.
Relief valve sticking. Remove and clean.
Relief setting too low. Readjust to proper setting.
Worn pump, motor or cylinder. Replace bad part.
Plugged filter. Change filter.
CONDITION POSSIBLE CAUSE POSSIBLE SOLUTION
Fo
r
Reference
Only

Manitowoc 1400A Specifications

General

Brand	Manitowoc
Model	1400A
Category	Construction Equipment
Language	English