Komatsu 830E-AC Shop Manual page 781

Trouble
Noise or squeal
Steering function slow
Irregular or unsteady
operation
Excessive heating
L10028
TROUBLESHOOTING CHART
(Steering Pump)
Possible Cause
Low compensator pressure setting.
Fluid too cold or viscosity too high.
Air leak at inlet connection.
Insufficient inlet oil.
Broken or worn piston/shoe assem-
bly.
Low pressure compensator pres-
sure setting.
Plugged filter or suction strainer.
Fluid level is reservoir is low or
supercharge is insufficient.
Air entering hydraulic system.
Worn piston pump.
Faulty output circuit components.
Operating pump above rated pres-
sure.
Low fluid level in reservoir.
Air entering hydraulic system.
Worn piston pump.
Worn or grooved cylinder wear plate
and/or port plate.
Faulty output circuit components.
Hydraulic Check-out Procedure
Suggested Corrective Action
Check compensator pressure setting.
Use proper viscosity oil or warm oil before
starting.
Inspect inlet hose and connections for
looseness.
Check for proper hydraulic tank oil level.
Check for clogged suction strainer. Make
sure suction line shut-off valve is open.
Repair or replace broken/worn parts.
Check and adjust compensator pressure
setting.
Replace filter element or clean suction
strainer.
Check for proper hydraulic tank oil level.
Inspect inlet hose and connections.
Repair or replace broken/worn parts.
Repair or replace relief valve or pressure
compensator valve.
Refer to "Pressure Check and Adjustment
Procedure", this Section.
Check for proper oil level in hydraulic tank.
Inspect inlet hose and connections.
Repair or replace worn components.
Repair or replace worn components.
Repair or replace relief valve or pressure
compensator valve.
L10-13