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6-13
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
YES
Is bucket or arm
operation
possible?
Does
counterbalance
spool move lightly
by hand?
Does the symptom
change when
relief valves in
travel motor are
exchanged?
Has travel spool
changed over
positively?
Does the symptom
change when A1
and A2 pump
discharge hoses
are exchanged?
Is travel brake
valve pressure
within standard
level?
Does travel spool
move?
NO
刔
Counter spool is
stuck.
Relief valve built
in travel motor is
faulty.
Control system is
defective.
Travel spool is
stuck.
Travel reduction
unit is faulty.
Travel motor is
out of order.
Hydraulic pump is
broken.
Travel relief
valves are faulty.
Disassemble
and repair or
replace.
Disassemble
and repair.
Disassemble
inspect and
repair.
Disassemble
and repair.
Disassemble
and repair.
Disassemble
and repair.
Disassemble
and repair.
Disassemble
and repair or
replace.
刔
5. TRAVEL SYSTEM
TRAVEL DOES NOT FUNCTION AT ALL ON ONE SIDE
1)
Do not metallic
particles come
out of drain port
in travel
reduction unit?
Cause
Remedy
Does the
symptom change
when LH/RH
travel relief valves
are exchanged?
YES
YES
NO