Maintenance, Troubleshooting, and Emergency Procedures
Maintenance, Troubleshooting, and Emergency Procedures
The exam wants a systematic responder, not a parts changer: read the symptom, protect people, relieve pressure, then diagnose.
Routine maintenance that prevents the call
- Grease boom pins, outrigger beams, and hopper points; change hydraulic filters and sample oil on schedule; precharge the accumulator with nitrogen only, per the manufacturer.
- Wear items: wear plate and ring, S-tube, piston cups, and rubber hose. Track them; do not wait for failure.
- Check clamp torque and gasket condition at every setup; whip-check every hose.
Blockage: the standard drill
Symptoms are a pressure spike, short or stalled strokes, boom vibration, and reduced output. Stop pumping, relieve pressure per the manufacturer, then try a few slow reverse strokes if the machine allows. If it does not clear, depressurize fully and break the line at the nearest joint downstream of the blockage. Never hammer a pipe, never open a clamp on a pressurized line, and never blow a line out with compressed air as a shortcut.
Worked example
Output drops and the gauge climbs steadily; the hopper is full and the mix looks normal. First check whether the pump is running faster than the line can take - slow down and watch the gauge. If pressure stays high at low speed, the restriction is in the line; check the reducer and the first elbows, the usual plug points, before tearing down the whole run.
Emergency actions
Hose burst or clamp failure: stop the pump, keep people back, relieve pressure before approaching. Power line contact: stay in the cab, warn others away, call the utility. Hydraulic injection: emergency room immediately, and tell them it was high-pressure hydraulic fluid.
Traps that cost marks
Opening a clamp to "check" before bleeding pressure; reverse-pumping at full speed; using the boom to lift or drag; restarting after a plug without inspecting the wear plate and gaskets.