Repair Service Manual

REPAIR MANUAL
1
KUBOTA Z402 and Z602 engines
REPAIR (cont’d)
Anomaly
Possible cause
Solution
Fuel mixed with
lubrication oil
Worn injection pump plunger
Change the pump element or pump
Faulty injector
Repair or change the injector
Injection pump
Change
Water mixed with
lubrication oil
Faulty cylinder head gasket
Change
Flaky casing or cylinder head
Change
Low oil pressure
Low motor oil
Top up
Clogged strainer
Clean
Discharge valve stuck by dirt
Clean
Fatigue or broken discharge valve spring
Change
Too much running gap of a crankshaft
bearing
Change
Too much running gap of a connecting
rod head bearing
Change
Too much running gap of a push rod
bushing
Change
Clogged oil passage
Clean
Inappropriate type of oil
Use the type of oil specified
Faulty oil pump
Repair or change
High oil pressure
Inappropriate type of oil
Use the type of oil specified
Faulty discharge valve
Change
Overheating engine
Low motor oil
Top up
Fan belt broken or loose
Change or adjust
Low coolant
Top up
Radiator honeycomb or fins clogged
Clean
Corroded radiator interior
Clean or change
Corroded coolant circuit
Clean or change
Faulty radiator plug
Change
Run with overload
Reduce the load
Faulty cylinder head gasket
Change
Bad injection timing
Adjust
Inappropriate fuel type
Use the fuel specified
Battery discharges
too fast
Low electrolyte
Fill distilled water and charge the battery
Slipping fan belt
Adjust belt tension or change it
Wiring disconnected
Reconnect
Rectifier disconnected
Change
Faulty fan generator
Change
Faulty battery
Change