Nortrac XT20 Owner's Manual page 44

Drive shaft and
sleeve become hot
4
(4-wheel drive
tractor).
Auxiliary box
5 noise (4-wheel
drive tractor).
2.16.1.5 Hydraulic Steering System Faults and Troubleshooting
Sequence
Fault
No.
Oil
1
leakage.
Heavy
2
steering.
Steering
3 column
failure.
Hydraulic
steering
4.
without
power.
Steering
5. is hard to
turn.
Operation Description
(1) The drive shaft is severely bent or
deformed creating friction.
(2) Speed gear is too high.
(3) Bearing or gear is severely worn.
Table 2-8 Hydraulic System Faults and Troubleshooting
Fault Reasons
(1) Rubber o-rings or bolts at various pipe joints are
damaged or loose.
(2) Hydraulic steering gear valve body, stator and rear
cover rubber o-rings are damaged.
(3) Rubber o-ring at the axle journal is damaged.
(4) Leaks in hub subassembly
(1) Not enough oil delivery to the gear oil pump. The
gear oil pump leaks inside or the oil screen inside
the steering oil tank is blocked (light at low speed
and heavy at high speed).
(2) Erratic steering cylinder movement when the
steering wheel is rotated.
(3) The oil level in the steering oil cylinder is
insufficient.
(4) Spring tension in the relief valve becomes weak,
or the steel ball is not sealed, light load is steering
lightly, and steering becomes heavier if load is
increased.
(5) Oil viscosity is too high.
(6) Steel ball check valve in the valve body fails; the
steering wheel is heavy when turning it slowly or
weak when turning sharply.
(7) Oil leakage from steering system, both inside and
outside.
(1) Linkage shaft opening is broken or deformed.
(2) Rotor and linkage shafts are improperly mounted.
(3) Steering oil cylinder piston or piston seal ring is
damaged.
(1) Clearance between the rotor and stator is too big
on pump.
(2) Driver does not feel endpoint strongly when
steering with the oil cylinder piston in the extreme
position; when manual steering, the steering wheel
rotates and oil cylinder does not move.
(1) The gap between valve inside and the valve sleeve
is too large.
(2) The gap between interlocking shaft and fork pin is
too large.
(3) The gap between the interlocking shaft and the
rotor is too large.
(4) The return spring plate is broken or too soft.
(1) Replace the drive shaft
(2) Put into low gear.
(3) Replace
38
Troubleshooting
(1) Replace the rubber ring
or tighten the bolt.
(2) Replace the rubber ring.
(3) Replace the rubber
o-rings.
(4) Tighten the bolts.
(1) Check the gear
pump. Clean the filter
screen.
(2) Discharge the air in the
system and check if air
exists in the oil suction
pipe.
(3) Fill oil to specified
height, clean the relief
valve and adjust the
spring pressure in the
valve.
(4) Replace parts
components.
(5) Drain oil and replace
with specified oil
(6) Replace valve.
(7) Troubleshoot the point
of the oil leakage and
repair or replce.
(1) Replace the coupled
axle.
(2) Refit.
(3) Replace
(1) Replace pump.
(2) Replace
(1) Replace.
(2) Replace.
(3) Replace.
(4) Replace.
oil
and