Excavators are the dynamos of construction, demolition, landscaping, and earthmoving. They’re built for tough conditions, but like any heavy machinery, they’re not immune to wear, damage, and occasional breakdowns. For operators and site managers, knowing the common failures to look out for can help prevent downtime, costly repairs, and – most importantly – safety risks.
Below, we explore some of the most frequent issues found during inspections and routine maintenance of excavators.
1. Hydraulic System Leaks and Failures
The hydraulic system powers almost every movement on an excavator – boom, arm, bucket, swing, and even travel. Common problems include:
- Hydraulic fluid leaks from hoses, connectors, cylinders, or the pump.
- Worn or damaged seals, especially in cylinders or valves.
- Contaminated hydraulic fluid, which can cause internal damage over time.
- Pump failure, often due to low fluid levels or overheating.
Tip: Regularly check for fluid puddles, slow or jerky movements, or odd noises under load.
2. Track and Undercarriage Wear
The undercarriage can account for up to 50% of an excavator’s maintenance costs. Issues here are often due to:
- Worn sprockets, rollers, or idlers from improper tensioning.
- Track misalignment, which increases wear and tear.
- Loose or missing track bolts and fasteners.
Tip: Keep tracks clean, maintain correct tension, and inspect the undercarriage after every shift, especially on rocky or abrasive terrain.
3. Engine Problems
Excavator engines are subject to harsh working environments. Common engine-related issues include:
- Dirty or clogged filters (air, fuel, oil) reducing performance or causing stalling.
- Coolant leaks leading to overheating.
- Battery or alternator failures that affect starting or electronic functions.
- Black or white smoke indicating fuel system issues or poor combustion.
Tip: Stick to manufacturer service intervals and always check fluid levels and filters before starting work.
4. Electrical Faults
Modern excavators rely heavily on electronics – especially for diagnostics, monitoring systems, and safety functions. Common electrical issues include:
- Faulty sensors leading to incorrect readings or false alarms.
- Damaged wiring or connectors, often caused by vibration or rodent damage.
- Control panel errors, sometimes due to software glitches or low voltage.
Tip: Use onboard diagnostics to monitor faults and always investigate dashboard warning lights immediately.
5. Structural Cracks and Weld Failures
Heavy digging and lifting create immense stress on the boom, arm, and chassis. Common signs of fatigue include:
- Cracks at weld joints, especially around the boom base and bucket linkage.
- Distorted arms or booms from overloading or impact.
- Wear on bucket pins and bushings, leading to loose connections.
Tip: Regularly inspect for signs of stress or cracking, especially on older machines or those used for heavy-duty tasks.
6. Swing Motor and Slew Ring Issues
Excavators rely on the slew ring bearing and swing motor to rotate the upper structure. Common failures include:
- Grinding noises during rotation – a sign of worn bearings.
- Oil leaks around the slew motor or bearing housing.
- Uneven or jerky rotation, which may indicate internal gear damage.
Tip: Don’t ignore unusual sounds or resistance during slewing – catching wear early can prevent major repairs.
Prevention Is Better Than Cure
Most excavator failures stem from neglecting routine inspections, operating outside of safe limits, or deferring maintenance. Simple daily checks, planned preventative maintenance, and statutory inspections (like PUWER and LOLER where applicable) can prevent minor issues from becoming major failures.
If you’re unsure about your excavator’s condition or haven’t had a thorough inspection recently, now’s the time to schedule one. Downtime on-site can be costly – both financially and in terms of safety.
Need Help?
We provide expert PUWER and LOLER inspections for excavators and other plant machinery throughout Newcastle, Durham & Sunderland, helping you stay compliant and safe. Get in touch to book an inspection or learn more about our services.
