What is the correct procedure for maintaining hydraulic hoses and fittings?

• A. Inspect for leaks only; replace hoses only when they fail.
• B. Over-tighten fittings to stop leaks.
• C. Replace hoses on a fixed schedule regardless of wear.
• D. Inspect regularly for wear, damage, leaks; replace as needed; ensure clean connections to prevent contamination.

Answer: (D)