Inspection, Diagnosis, and Repair Procedures
Core concepts
Know systematic diagnosis: gather symptoms, verify the complaint, form a hypothesis, test, and confirm repair. Use service information, fault codes, and measurement. Understand preventive maintenance intervals, fluid checks, torque specifications, and documentation. Safety procedures include lockout/tagout, relieving stored energy (hydraulic, electrical, spring), and lifting with rated equipment. Know how to write a repair order and verify a repair with a functional test.
Traps
Questions often reward jumping to a part replacement without verification, or skipping the confirm step after repair. Another trap is ignoring stored energy in accumulators or springs before disassembly. Do not assume a fault code identifies the failed component; it identifies the circuit or condition. Documentation and re-test are commonly tested.
Rule of thumb
Follow verify-test-repair-confirm. Relieve stored energy before work, use rated lifting devices, and re-test under the original operating condition. If a repair does not resolve the complaint, revisit the diagnosis rather than replacing more parts.
Worked example
A hydraulic lift is slow. Verify the complaint under load, check oil level and filter, measure pump flow and relief pressure, then test the cylinder for internal bypass. Replace only the confirmed faulty component and re-test lift speed under load. Document measurements and the final functional test.