Komatsu 830E, Shop Manual

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L10-8 Hydraulic Check-out Procedure 05/03 L10016
TROUBLESHOOTING CHART
(Steering Pump)
Trouble Possible Cause Suggested Corrective Action
No pump output
Trapped air inside steering pump.
Broken pump drive shaft.
Excessive circuit leakage.
No oil to pump inlet.
Bleed trapped air. Refer to “Pressure Check
And Adjustment Procedure”, this Section.
Replace pump drive shaft.
Check for loose fittings, broken or cracked
tubes.
Check hydraulic tank oil level. Make sure
shut-off valve is open.
Low pump output
Low pump pressure.
Compensator valve, seat, spring or
packing failure.
Worn or scored pistons and bores.
Maximum volume stop limiting
pump stroke.
Worn or damaged piston shoes,
swashblock or swashblock wear
plate.
Worn or grooved cylinder wear plate
and/or port plate.
Restricted inlet.
Insufficient inlet oil.
Check or adjust compensator pressure set-
ting.
Repair or replace compensator.
Repair or replace pistons or pump housings.
Turn volume stop screw counterclockwise.
Tighten jam nut.
Repair or replace defective parts.
Repair or replace defective parts.
Clear restriction. Make sure suction line
shut-off valve is open. Clean suction
strainer.
Check for proper hydraulic tank oil level and
make sure suction line shut-off valve is
open.
Unresponsive or slug-
gish control
Control piston seals broken or dam-
aged.
Swashblock saddle bearings worn
or damaged.
Repair or replace broken parts.
Repair or replace broken parts.
Loss of pressure
Faulty output circuit components.
Worn piston pump.
Worn or grooved cylinder wear plate
and/or port plate: wear plate and/or
port plate separation from cylinder,
each other or valve plate.
Worn pistons, shoes or piston
bores.
Repair or replace relief valve or pressure
compensator valve.
Repair or replace worn parts.
Repair or replace worn parts.
Repair or replace worn parts.
Excessive or high peak
pressure
Faulty output circuit components. Repair or replace relief valve or pressure
compensator valve.