Troubleshooting
78Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Lamp does not glow brightly even when the engine runs at high speed; Lamp flickers while engine is running | Defective wiring; Defective adjustment of belt tension | (Check, repair loose terminals, disconnections); Check, Adjust fan belt tension. For details, see EVERY 250 HOURS SERVICE |
| Even when the engine is rotating, the charge caution pilot lamp does not go out | Defective alternator; Defective wiring; Defective adjustment of fan belt tension | (Replace); (Check, repair); Check, Adjust fan belt tension. For details, see EVERY 250 HOURS SERVICE |
| Abnormal noise is generated from alternator | Defective alternator | (Replace) |
| Starting motor does not turn when starting switch is turned to START | Defective wiring; Insufficient battery charge; Defective starting motor | (Check, repair); Charge; (Check, repair) |
| Pinion of starting motor keeps going in and out | Insufficient battery charge | Charge |
| Starting motor turns engine sluggishly | Insufficient battery charge; Defective starting motor | Charge; (Replace) |
| Starting motor disengages before engine starts | Defective wiring; Insufficient battery charge | (Check, repair); Charge |
| Preheating pilot lamp does not light up | Defective wiring; Defective heater relay, preheating water temperature sensor; Defective preheating pilot lamp | (Check, repair); (Replace); (Replace) |
| Even when engine is stopped, charge caution pilot lamp does not light up (starting switch at ON position) | Defective wiring; Defective monitor | (Check, repair); (Replace) |
| Even when engine is stopped, engine oil pressure caution pilot lamp does not light up (starting switch at ON position) | Defective pilot lamp; Defective pressure caution lamp; Defective monitor | (Replace); (Replace); (Replace) |
| Engine is running but machine does not move | Parking brake is applied | Release parking brake |
| Engine is running but machine does not move | Directional lever is not shifted properly | Shift lever properly |
| Engine is running but machine does not move | Lack of oil in hydraulic tank | Add oil to specified level. See WHEN REQUIRED |
| Even when engine is run at full throttle, machine only moves slowly and lacks power | Lack of oil in hydraulic tank | Add oil to specified level. See WHEN REQUIRED |
| Even when engine is run at full throttle, machine only moves slowly and lacks power | Screen is clogged | Disassemble, clean |
| Oil overheats | Too much oil or too little oil | Add or drain oil to specified level. See WHEN REQUIRED |
| Oil overheats | Machine is not traveling in correct speed range | Place in correct speed range |
| Oil overheats | Torque converter is stalled for long periods | Reduce stall time |
| Oil overheats | Engine is overheating | (Check engine) |
| Noise generated (transmission) | Lack of oil in transmission case | Add oil to specified level. See WHEN REQUIRED |
| Noise generated (axle) | Lack of oil | Add oil to specified level. See WHEN REQUIRED |
| Noise generated (axle) | Improper oil used (for machines with limited-slip differential) | Change to specified oil |
| Brake is not applied when pedal is depressed | Disc has reached wear limit | (Replace disc) |
| Brake is not applied when pedal is depressed | Defective hydraulic system | |
| Brake is not applied when pedal is depressed | Lack of oil | Add oil to specified level. See EVERY 100 HOURS SERVICE |
| Brake is not applied when pedal is depressed | Air in brake line | Bleed air. |
| Brake drags or not applied | Vent hole of brake valve is clogged | Clean |
| Brakes squeal | Disc is worn | (Replace disc) |
| Brakes squeal | Large amount of water in axle oil | Change axle oil |
| Brakes squeal | Deteriorated axle oil due to overuse of brake | Change axle oil |
| Poor braking effect (parking brake) | Linkage is loose | Adjust |
| Poor braking effect (parking brake) | Disc is worn | (Replace disc) |
| Brake drags or remains applied (parking brake) | Lack of oil in transmission case | Add oil to specified level. See WHEN REQUIRED |
| Brake drags or remains applied (parking brake) | Screen is clogged | (Disassemble, clean) |
| Steering wheel is heavy | Defective hydraulic system | |
| Steering wheel is heavy | Lack of oil | Add oil to specified level. See EVERY 100 HOURS SERVICE |
| There is play in steering wheel | Steering cylinder pin is loose | Grease bearing. Or replace pin and bushing where there is play |
| There is play in steering wheel | Defective hydraulic system; Lack of oil | Add oil to specified level. See EVERY 100 HOURS SERVICE |
| Bucket lacks lifting power; Bucket takes time to go up | Lack of oil | Add oil to specified level. See EVERY 100 HOURS SERVICE |
| Bucket lacks lifting power; Bucket takes time to go up | Clogged hydraulic filter | Replace cartridge. See EVERY 2000 HOURS SERVICE |
| Excessive bubbles in oil | Poor quality oil | Replace with good quality oil |
| Excessive bubbles in oil | Lack of oil | Add oil to specified level. See EVERY 100 HOURS SERVICE |
| Excessive bubbles in oil | Air entering oil line | Bleed air. See EVERY 2000 HOURS SERVICE |
| Lack of oil pressure | Lack of oil causes pump to suck in air | See EVERY 100 HOURS SERVICE for details of adding oil; See EVERY 2000 HOURS SERVICE for details of bleeding air |
| Irregular movement of cylinder | Lack of oil | Add oil to specified level. See EVERY 100 HOURS SERVICE |
| Engine oil pressure caution pilot lamp lights up | Low engine oil pan oil level (sucking in air) | Add oil to specified level. See CHECK BEFORE STARTING |
| Engine oil pressure caution pilot lamp lights up | Clogged oil filter cartridge | Replace cartridge. See EVERY 500 HOURS SERVICE |
| Engine oil pressure caution pilot lamp lights up | Defective tightening of oil pipe joint, oil leakage from damaged part | (Check, repair) |
| Engine oil pressure caution pilot lamp lights up | Defective monitor | (Replace) |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Low cooling water level, leakage of water | Check, add cooling water, repair. See WHEN REQUIRED |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Defective fan pump motor | (Check, repair) |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Dirt or scale accumulated in cooling system | Change cooling water, clean inside of cooling system. See WHEN REQUIRED |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Clogged radiator fin or damaged fin | Clean or repair. See WHEN REQUIRED |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Defective thermostat | (Replace thermostat) |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Defective thermostat seal | (Replace thermostat seal) |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Loose radiator filler cap (high altitude operation) | Tighten cap or replace packing |
| Steam is emitted from top part of radiator (pressure valve); Water temperature gauge is in red range; Coolant temperature monitor lights up | Defective monitor | (Replace) |
| Water temperature gauge is in white range on left | Defective thermostat | (Replace thermostat) |
| Water temperature gauge is in white range on left | Defective monitor | (Replace) |
| Engine does not start when starting motor is turned | Lack of fuel | Add fuel. See CHECK BEFORE STARTING |
| Engine does not start when starting motor is turned | Air in fuel system | Repair place where air is sucked in |
| Engine does not start when starting motor is turned | No fuel in fuel filter | Fuel filter with fuel. See EVERY 500 HOURS SERVICE |
| Engine does not start when starting motor is turned | Defective injection pump or nozzle | (Replace pump or nozzle) |
| Engine does not start when starting motor is turned | Starting motor cranks engine too slowly | See ELECTRICAL SYSTEM |
| Engine does not start when starting motor is turned | Starting motor does not turn | See ELECTRICAL SYSTEM |
| Engine does not start when starting motor is turned | Preheating pilot lamp does not light up | See ELECTRICAL SYSTEM |
| Engine does not start when starting motor is turned | Defective valve clearance (Defective compression) | (Adjust valve clearance) |
| Exhaust gas is white or blue | Too much oil in oil pan | Add oil to specified level. See CHECK BEFORE STARTING |
| Exhaust gas is white or blue | Improper fuel | Change to specified fuel |
| Exhaust gas occasionally turns black | Clogged air cleaner element | Clean or replace. See WHEN REQUIRED |
| Exhaust gas occasionally turns black | Defective nozzle | (Replace nozzle) |
| Exhaust gas occasionally turns black | Defective compression | (See defective compression above) |
| Exhaust gas occasionally turns black | Defective turbocharger | Clean or replace turbocharger |
| Combustion noise occasionally makes breathing sound | Defective nozzle | (Replace nozzle) |
| Abnormal noise generated (combustion or mechanical) | Low grade fuel being used | Change to specified fuel |
| Abnormal noise generated (combustion or mechanical) | Overheating | Refer to "Water temperature gauge is in red range" as above |
| Abnormal noise generated (combustion or mechanical) | Damage inside muffler | (Replace muffler) |
| Abnormal noise generated (combustion or mechanical) | Excessive valve clearance | (Adjust valve clearance) |
Fault codes and symptom→remedy steps extracted from this unit’s service/owner documentation; verify against the official manual before servicing.
Replacement parts listed for the Komatsu WA470
14| Overhaul Rebuild Kit | FridayParts $2200.00 |
| Gear Pump 705-12-38000 | FridayParts $1200.99 |
| Shaft Assemly 421-20-34511 4212034511 421-20-34650 4212034650 | FridayParts $809.38 |
| Radiator 20Y-03-56110 | FridayParts $784.99 |
| 4 Pieces Cabin Rubber Cushion Viscous Mount 423-54-41631 | FridayParts $487.59 |
| Pin 421-70-21910 | FridayParts $266.99 |
| Front Final Brake Center Axle Seal Kit 56D-23-13461 | FridayParts $181.00 |
| Fuel Injector 6251-11-3200 | FridayParts $160.02 |
| Parking Switch 423-06-45370 423-06-45371 | FridayParts $150.99 |
| Floating Seal 287-33-00010 | FridayParts $134.99 |
| Floating Seal 423-33-00021 | FridayParts $134.99 |
| Dump Cylinder Seal Kit 707-99-73010 | FridayParts $95.68 |
| Limiter ND095400-0310 ND0954000310 | FridayParts $82.45 |
| Piston Cooling Nozzle CU3080708 | FridayParts $39.13 |
Aftermarket listings whose supplier names this air compressor. Check the part number against your serial number before ordering.
Aftermarket parts that fit this air compressor
16287-33-00010 FridayParts $134.99 423-33-00021 FridayParts $134.99 707-99-73010 FridayParts $95.68 42120-34511 KuduParts $784.00 FridayParts $809.38 42120-34650 KuduParts $784.00 FridayParts $809.38 ND0954000310 FridayParts $82.45 423-06-45370 FridayParts $150.99 423-06-45371 FridayParts $150.99 705-12-38000 KuduParts $1175.00 FridayParts $1200.99 CU3080708 FridayParts $39.13 56D-23-13461 FridayParts $181.00 6251-11-3200 FridayParts $160.02 SinoCMP $289.00 423-54-41631 FridayParts $487.59 421-70-21910 FridayParts $266.99 20Y-03-56110 FridayParts $784.99 FP-XP-0034380
Parts listed by aftermarket suppliers as fitting this air compressor — leads compiled from supplier catalogs; verify the exact part for your serial number.
Available documents
Parts manualService manual
About
Komatsu WA470 — air compressor. Specifications and parts compiled from manufacturer documents.