5 - 2
Fault finding (cont’d)
Section F
Transmission
9803/6020
Section F
5 - 2
Issue 1
Traction Motor/Reduction Gear
Symptom
8
High temperature of reduction
gear case surface.
9
Does not travel in a straight line
at ‘low speed’.
10
Does not travel in a straight line
at ‘high speed’.
11
Does not speed up - pump
delivery slow.
12
Does not speed up.
13
Abnormal sound.
14
Does not change from low speed
to high speed.
Possible cause
a
Insufficient gear oil.
b
Pitching is generated in bearing.
c
Entry of hydraulic oil into gear
case.
a
Uneven delivery flow between
right and left sides.
b
Uneven motor drain leakage
between right and left sides.
a
Uneven delivery flow between
right and left sides.
b
Uneven motor drain between
right and left sides.
c
Non-uniform operation of right
and left brake valves.
d
Drop in relief pressure in right or
left control valve.
a
Pump regulator and/or related
parts faulty.
b
Leakage outside pump is
excessive.
a
Internal leakage is excessive.
a
Motor or reduction gear is
broken.
b
Vibration of pipework.
a
Faulty operation of high pressure
selection check valve.
b
Faulty operation of switching
valve.
c
Low pilot pressure.
d
Faulty operation of 2-speed
switching piston.
Remedy
Top up oil
Dismantle and renew damaged parts.
Renew oil seal.
Repair pump and/or regulator.
Dismantle motor/reduction gear and
repair.
Repair pump and/or regulator.
Dismantle motor/reduction gear and
repair.
Renew brake valve and/or rear flange.
Set correct pressure and/or renew
relief valve.
Repair regulator and/or related parts.
Repair or renew pump.
Dismantle reduction gear and repair.
Dismantle motor and/or reduction
gear and repair.
Clamp pipework securely.
Inspect and repair or renew if
necessary.
Check to see if spool is normal, and
repair or renew if necessary.
Set to specified pressure.
Inspect and repair or renew if
necessary.
Summary of Contents for JS70
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Page 189: ...Section E Section E Hydraulics 9803 6020 Issue 1 33 4 33 4 Control Valves Control Valve 291360...