What bench or on-engine tests verify fuel system integrity after overhaul?

What bench or on-engine tests verify fuel system integrity after overhaul?

• A. Visual inspection of lines and pump only.
• B. Leakage checks only.
• C. Pressure tests for lines and pump, fuel flow tests at given pressures, and leakage checks; engine run tests for proper mixture.
• D. Visual flow test at idle.

Answer: (C)

The main idea is that confirming fuel system integrity after overhaul requires both a thorough bench assessment and an on-engine check to prove the system can hold pressure, deliver the right amount of fuel, and produce the correct fuel-air mixture in operation. Pressurizing the lines and pump tests their ability to hold and maintain service pressure—any loss or drop reveals leaks or weak components. Conducting fuel flow tests at specified pressures shows the pump and metering path deliver the required volume under operating conditions, not just at rest. Leakage checks are essential to catch any small leaks at joints, fittings, or seals that could undermine performance or safety. Finally, running the engine verifies that, under real operating conditions, the fuel system provides the correct mixture and that the engine responds properly across RPM ranges without lean or rich conditions. Visual inspection alone or idle checks won’t reveal flow capability, pressure retention, or mixture correctness, so the comprehensive approach is the best choice.

The main idea is that confirming fuel system integrity after overhaul requires both a thorough bench assessment and an on-engine check to prove the system can hold pressure, deliver the right amount of fuel, and produce the correct fuel-air mixture in operation. Pressurizing the lines and pump tests their ability to hold and maintain service pressure—any loss or drop reveals leaks or weak components. Conducting fuel flow tests at specified pressures shows the pump and metering path deliver the required volume under operating conditions, not just at rest. Leakage checks are essential to catch any small leaks at joints, fittings, or seals that could undermine performance or safety. Finally, running the engine verifies that, under real operating conditions, the fuel system provides the correct mixture and that the engine responds properly across RPM ranges without lean or rich conditions. Visual inspection alone or idle checks won’t reveal flow capability, pressure retention, or mixture correctness, so the comprehensive approach is the best choice.