Preventive Maintenance & Troubleshooting Flashcards

A plant's maintenance records show a component failing repeatedly every 3–4 months. The BEST long-term corrective action is to:

Answer: Perform root cause analysis (RCA) to eliminate the underlying cause

Repetitive failures indicate an unresolved root cause; RCA identifies and eliminates the underlying problem rather than just managing the symptom.

What is the recommended minimum distance between a motor shaft coupling and a technician's body during operation, per general industrial safety practice?

Answer: Maintain a safe distance with all guards in place — never operate without guards

OSHA and industrial safety standards require rotating coupling guards to be in place during operation; no specific distance substitutes for proper guarding.

A technician observes that a newly installed chain drive is noisy and vibrating excessively. After verifying correct alignment, the NEXT most likely cause to check is:

Answer: Excessive chain slack or incorrect chain pitch

Excessive chain slack causes the chain to slap and vibrate; incorrect pitch causes the chain not to mesh properly, both resulting in noise and vibration.

In ultrasonic testing used for PM, what condition is indicated by a high-pitched hissing sound detected from a compressed air line fitting?

Answer: A leak at the fitting

Ultrasonic detectors pick up the high-frequency hissing sound produced by turbulent air escaping through a leak at fittings, valves, or seals.

A technician checks a roller bearing using a stethoscope and hears a regular clicking sound that increases with speed. This symptom is MOST consistent with:

Answer: A defective rolling element (spalled ball or roller)

A regular clicking or ticking that scales with shaft speed is characteristic of a damaged rolling element contacting the race once per revolution.

When draining and replacing hydraulic fluid as part of a PM schedule, the MOST important step before refilling is:

Answer: Flushing the system and replacing all hydraulic filters

Flushing removes contaminated fluid and degraded particles, while replacing filters prevents old contamination from immediately degrading the fresh fluid.

A maintenance team implements a 5-Why analysis after an unexpected equipment failure. The purpose of this technique is to:

Answer: Systematically trace a problem back to its root cause by asking 'why' repeatedly

The 5-Why technique iteratively asks 'why' at each level of a problem to move past symptoms and identify the true root cause driving the failure.