🔍 Key Concepts

• Governor hydraulic systems on marine diesel engines • How contaminants typically enter closed hydraulic systems • Effects of different contaminants (moisture, dirt, air, acid) on precision hydraulic components

💭 Think About

• Which of these contaminants is most likely to enter through normal operation, minor leaks, or imperfect seals in a governor system? • In a fine-clearance hydraulic mechanism, which contaminant would most commonly be introduced from the surrounding engine-room environment? • Think about maintenance tasks: when lines are opened or filters are changed, which contaminant is most easily introduced if procedures are not perfect?

✅ Before You Answer

• Consider which contaminant is most prevalent around engines and piping, not just harmful. • Ask: Which contaminant is often trapped by filters, and therefore a known, frequent concern in hydraulic systems? • Remember that closed hydraulic systems are usually vented or bled — which option fits with common issues seen during bleeding and refilling?