In a hydraulic brake system, if there is no free-play, what could be the issue?

Answer: B — closed compensating port

In a hydraulic brake system, the issue of having no free-play typically indicates that there is a problem with the compensating port in the master cylinder. When the compensating port is closed, it prevents brake fluid from flowing back to the reservoir, leading to a situation where the brake pads or shoes could remain in contact with the rotors or drums. This constant contact can result in overheating, increased wear, and diminished braking performance. The compensating port's role is crucial as it allows fluid to return to the reservoir when the brake pedal is released. By blocking this port, excessive pressure builds up, impacting the system's ability to function correctly. This scenario would cause the brakes to drag, presenting as a lack of free play in the brake system. Understanding the hydraulic brake system's components and their functions helps in diagnosing issues effectively, especially entities like the compensating port, which plays a vital role in maintaining proper brake system operation.