System Troubleshooting Chart - Komatsu 730E Operation & Maintenance Manual

OM4206 06/06
Automatic Lubrication System

SYSTEM TROUBLESHOOTING CHART

NOTE: If the following procedures do not correct the problem, contact a factory authorized service center.
PROBLEM
Pump Does Not Operate.
Pump Will Not Prime.
Pump Will Not Build
Pressure.
Injector Indicator Stem
Does Not Operate.
Pressure Gauge Does Not
Register Pressure.
POSSIBLE CAUSES
Lubrication system not grounded.
Electrical power loss.
Timer malfunction.
Solenoid valve malfunctioning.
Relay malfunctioning.
Motor or pump malfunction.
NOTE: On initial startup of the lubrication system, the timing capacitor will not
contain a charge. Therefore, the first timing cycle will be about double in length
compared to the normal interval. Subsequent timer cycles must be as specified.
Low lubricant supply.
Air trapped in lubricant supply line.
Lubricant supply line leaking.
Vent valve leaking.
Pump worn or scored.
NOTE: During operation, the injector indicator stem will move into the body of the
injector when pressure builds properly. When the system vents (pressure
release), the indicator stem will again move out into the adjusting yoke.
Malfunctioning injector - usually
indicated by the pump building
pressure and then venting.
All injectors inoperative - pump
build up not sufficient to cycle injec-
tors.
No system pressure to pump motor.
No 24VDC signal at pump solenoid.
Pressure reducing valve set too
low.
24V Relay (RB7K8 or RB7K5) may
be defective.
Maintenance - Section 42
SUGGESTED CORRECTIVE ACTION
Correct grounding connections to pump
assembly and truck chassis.
Locate cause of power loss and repair.
24VDC power required. Ensure key
switch is on.
Replace timer assembly.
Replace solenoid valve assembly.
Replace relay.
Repair or replace motor and/or pump
assembly. Refer to the Service manual for
rebuild instructions.
Dirt in reservoir, pump inlet clogged, filter
clogged.
Prime system to remove trapped air.
Check lines and connections to repair
leakage.
Clean or replace vent valve.
Repair or replace pump assembly. Refer
to the Service manual for rebuild instruc-
tions.
Replace individual injector assembly.
Service and/or replace pump assembly.
Refer to the Service manual for rebuild
instructions.
Check hydraulic hose from steering sys-
tem.
Determine problem in 24VDC electric sys-
tem.
Refer to Pressure Control Valve Adjust-
ment.
Replace relay.
Page 42-15