Daedong DSC48, Workshop Manual

Page: 226 / 290

6
-12 Apr. 2007
DSC48
1.5.2 TROUBLESHOOTING WITH HYDRAULIC SYSTEM
If each solenoid value is correctly operating when its corresponding manual push button is pressed and if the hydraulic
system is believed to be the cause of malfunction, perform the following troubleshooting. The next system to be checked is
the electric system of each controller.
Symptom Cause Action
The cylinder does not
operate. • Air sucked in
(suction pipe, hose, oil fi lter, etc.)
• Insuf fi cient or incorrect oil level
• Clogged hydraulic fi lter
• Repair
• Replenish or replace
• Clean or replace
Only the steering cylinder
does not work. Or it takes
time to operate. • Abnormal low pressure relief valve
• Abnormal hydraulic pump (D)
• Abnormal steering control solenoid valve
• Abnormal steering cylinder
(Worn or damaged cylinder, damaged O-ring)
• Loose or abnormal pipe or connecting system
• Repair or replace
• Replace
• Replace
• Replace
• Repair
The brake does not work
when operating the power
steering lever. • Unadjusted power brake cable
• Abnormal low pressure relief valve
• Abnormal steering control solenoid valve
• Abnormal steering cylinder
(Worn or damaged cylinder, damaged O-ring)
• Adjust
• Repair
• Replace
• Replace
The reaping unit cannot be
lifted nor operated. • Abnormal high pressure relief valve
• Abnormal hydraulic pump
• Loose pipe or coupler between hydraulic pump and
valve unit
• Abnormal reaping unit lifting solenoid valve
• Repair
• Replace
• Repair
• Replace
The reaping unit is
automatically lowered
without any operation. • Abnormal reaping unit lowering solenoid valve
• Abnormal reaping unit cylinder
(Worn or damaged cylinder, damaged O-ring)
• Loose or abnormally installed pipe or coupler
• Replace
• Replace
• Repair
Abnormal noise occurs. • Relief valve in operation
(Overload- Lowly set pressure)
• Air sucked in (suction pipe, fi lter, etc.)
• Vibration occurred by pipe contact or resonance
with other parts
• Clogged hydraulic fi lter
• Damaged hydraulic pump
• Check and repair
• Repair
• Repair
• Clean or replace
• Replace
Oil temperature is
abnormally high. • Leaked hydraulic fi lter (worn or damaged)
• Oil leak from control valve
• Relief valve in operation
(Overload-Lowly set pressure)
• Replace
• Repair or replace
• Repair or replace