Pre-operation Inspection, Daily Maintenance, and Servicing
Pre-operation Inspection, Daily Maintenance, and Servicing
This domain tests the daily walk-around and safe servicing. The exam expects you to find defects before they fail, check fluids correctly, and isolate energy before maintenance.
Core rules
- Walk around the machine: leaks, chafed hoses, cylinder scoring, loose pins, missing teeth, guards, ROPS/FOPS damage, seatbelt, fire extinguisher, lights, horn, travel alarm, mirrors, and camera.
- Check engine oil, coolant, hydraulic oil, and fuel with the machine level and the attachment lowered. Check hydraulic oil at the temperature stated in the manual.
- Measure track sag at the specified point; adjust with the grease tensioner only per manual. Never over-pressurize.
- Grease pins and bushings at the stated interval; clean fittings before greasing.
- Drain water from the fuel/water separator; inspect air filter and battery; keep breathers clean.
- For service: lower the attachment, stop the engine, lock out, relieve hydraulic pressure, and support raised components.
- Tag out defects; do not operate a machine with a safety defect.
Worked example
You find a damp spot and a pinhole on a boom hose. Reasoning: a pinhole can inject hydraulic fluid through skin at high pressure, causing serious injury. Do not wipe it with a hand or tighten the fitting under pressure. Shut down, relieve pressure, replace the hose, and check for chafing that caused the damage.
Traps
- Checking hydraulic oil with the engine running or attachment raised.
- Treating a weeping hose as a minor leak.
- Running a loose track until it derails.
- Using ether or incorrect fluids.