What must the power steering hydraulic system be free of?

The power steering hydraulic system must be free of leaks to function properly. Leaks can result in a loss of hydraulic fluid, which is essential for the system to provide the necessary assist in steering. If the levels of hydraulic fluid drop due to leaks, it can lead to reduced steering efficiency and can even compromise the safety of the vehicle. The integrity of the hydraulic system is crucial for ensuring that the driver can maneuver the vehicle easily, especially at lower speeds or during parking maneuvers.

In contrast, while dust, oil, and friction may affect other systems or components, they do not specifically impair the hydraulic operation of the power steering as leaks do. Dust could potentially introduce contaminants, but it is not as critical as the presence of proper hydraulic fluid levels. Oil is typically a part of the fluid mix but not in a leaking context, while friction is a mechanical issue that pertains more to the movement of components rather than the hydraulic fluid aspect directly. Ensuring that the power steering system is free from leaks is vital for maintaining its efficiency and reliability.