Excavator troubleshooting, symptom by symptom

Start from what the machine is doing. Each guide lists the symptoms, the causes that actually produce them, and how to tell the causes apart before buying anything.

The expensive mistake in repair work is not misdiagnosing a part — it is replacing a good part because nobody tested it first. Each guide below works the same way: what the operator notices, which causes produce exactly that pattern, and the test that separates them. Where two faults look identical from the cab, the guide says so and gives you the check that tells them apart.

All troubleshooting guides

Hydraulic pump failure symptomsWarm-up behavior, standby pressure and flow — what actually proves it is the pump Excavator loses hydraulic power when warmGood when cold, weak when hot — what the temperature dependence proves Excavator slow travel speedSlow or single-side travel — solenoid, center joint, final drive or relief Excavator swing not working or swinging weaklySwing dead, weak, drifting or noisy — brake, motor, relief or gearbox Excavator overheatingEngine hot under load — radiator, thermostat, fan or genuine overload Black smoke from an excavatorOver-fueling or air starvation — air first, fuel second White smoke and blue smoke from an excavatorCoolant or oil in the cylinder — white and blue point different directions Excavator engine will not startCrank speed, safety lock, fuel, compression — in that order Boom and arm drift, and why a load will not holdSag or drift under load — seals, holding valve or spool leakage Track comes off an excavatorDerailment — tension, wear pattern and operating cause Final drive noise and overheatingTravel gearbox noise, heat or metal — seal, bearing or gear damage Excavator electrical faults and fault codesRead the code first — and suspect connectors before control units Excavator has poor digging forceWeak digging — separate hydraulic limit from engine limit Hydraulic oil overheatingHydraulic oil hot — relief leakage, cooler or load