Komatsu 830E-AC Shop Manual page 778

Trouble
Slow steering, hard
steering or loss of
power assist
Drift - Truck veers
slowly in one direction
Wander - Truck will not
stay in straight line
Slip - A Slow move-
ment of steering wheel
fails to cause any
movement of the
steered wheels
Spongy or soft steering
Erratic steering
Free Wheeling - Steer-
ing wheel turns freely
with no back pressure
or no action of the front
wheels
L10-10
TROUBLESHOOTING CHART
(Steering Circuit)
Possible Cause
Overloaded steering axle.
Malfunctioning relief valve. System
pressure lower than specified.
Worn or malfunctioning pump.
Rod end of cylinder slowly extends
without turning the steering wheel.
Worn or damaged steering linkage.
Air in system due to low oil level,
pump cavitation, leaking fittings,
pinched hoses, etc.
Loose cylinder piston.
Broken neutral position springs in
steering control unit.
Improper toe-in setting.
Bent linkage or cylinder rod.
Severe wear in steering control
valve.
Leakage of cylinder piston seals.
Worn steering control valve.
Low oil level.
Air in hydraulic system. Most likely
air trapped in cylinders or lines.
Air in system due to low oil level,
cavitating pump, leaky fittings,
pinched hose, etc.
Loose cylinder piston.
Lower splines of column may be
disengaged or damaged.
No flow to steering valve can be
caused by:
1. Low oil level
2. Ruptured hose
3. Broken cardan shaft pin (steering
unit)
Hydraulic Check-out Procedure
Suggested Corrective Action
Reduce axle loading.
Replace relief valve.
Replace pump. See steering pump trouble-
shooting chart.
A small rate of extension may be normal on
a closed center system.
Replace linkage and check alignment or
toe-in of the front wheels.
Correct oil supply problem and/or oil leak-
age.
Repair or replace defective components.
Replace neutral position springs.
Adjust.
Repair or replace defective components.
Repair steering control valve.
Replace seals.
Replace steering control valve.
Service hydraulic tank and check for leak-
age.
Bleed air from system. Positioning ports on
top of cylinder will help avoid trapping air.
Correct condition and add oil as necessary.
Repair or replace cylinder.
Repair or replace steering column.
1. Add oil and check for leakage
2. Replace hose
3. Replace pin
L10028