What is a possible indicator that a fitting is loose?

Fluid leakage around the fitting area is a clear and immediate indication that a fitting may be loose. When a fitting is properly tightened, it forms a secure seal that prevents fluid from escaping. If the fitting becomes loose, the integrity of this seal is compromised, leading to the possibility of fluid escaping. This leakage not only signifies that the fitting is not holding securely but can also result in operational inefficiencies, potential safety hazards, and increased maintenance costs if not addressed promptly.

In contrast, changes in color of the fluid may indicate contamination or a different issue unrelated to the fitting's integrity. Increased noise from the system can suggest operational problems but does not specifically point to a loose fitting. High temperature of the fluid might indicate issues like overheating or improper fluid type but again does not directly correlate with fitting tightness. Thus, fluid leakage serves as the most direct and observable indicator of a loose fitting, making it the correct choice.