What type of fluid would indicate contamination if found in the master cylinder reservoir?

• A. Clear fluid
• B. Purple fluid
• C. Green fluid
• D. Brown fluid

Answer: (B)

The presence of purple fluid in the master cylinder reservoir would indicate contamination. Typically, brake fluid is a clear, slightly amber-colored liquid, and any deviation from this can suggest that the fluid has been mixed with another substance or has undergone degradation due to moisture absorption or contamination from other fluids.

Purple fluid is often associated with various automotive fluids, particularly those from power steering systems or transmission fluids, which are not compatible with brake fluid. Such contamination can severely impair brake system performance, as these fluids may not provide the necessary hydraulic properties required for effective braking. Hence, identifying purple fluid would serve as a warning sign that the brake system needs immediate attention to avoid potential failure.

Other colors such as clear, green, or brown do not have the same implications regarding contamination specific to brake fluid as purple does. Clear fluid may represent healthy brake fluid, green fluid may be indicative of a different system (like some types of antifreeze or coolant), while brown fluid could suggest brake fluid that has degraded due to moisture but doesn't definitively indicate contamination with another fluid. Thus, the identification of purple fluid is critical for recognizing contamination in the brake system.