What indicates a need for replacement of struts in a vehicle?

The indication that struts need replacement is primarily characterized by excessive bounce, fluid leaks, or visible damage. Excessive bounce happens when the struts can no longer effectively dampen the movements of the suspension, leading to a bouncy ride that impacts handling and stability. Fluid leaks around the strut indicate that the internal hydraulic fluid is escaping, which compromises the strut's ability to absorb shocks and maintain proper vehicle control. Visible damage, such as dents or cracks, can further compromise the strut's functionality, necessitating replacement for safety and performance reasons.

In contrast, the other choices refer to issues that may be related to different components of the vehicle. Low tire pressure and worn brake pads pertain to tire and brake maintenance, while exhaust noises and engine misfires are linked to engine performance problems. Lastly, unresponsive steering and hard braking are indicative of issues within the steering or braking systems, rather than a direct indication of strut failure. Thus, the first option specifically addresses the signs related to strut condition and their functional role in vehicle suspension.