What causes a car to lose power steering?
2 Answers
The reasons for a car losing power steering are: 1. The vehicle lacks a power steering system: Cars without power steering require significant effort to turn the wheel. Currently, only a very few models lack power steering. 2. Power steering system failure: Power steering is a device in vehicles that uses compressed air, high-pressure oil, or other control mechanisms to make steering easier. Due to limited human strength, large vehicles often employ various "power assist" devices (technically called "servo mechanisms"). Taking the servo-assisted hydraulic braking system as an example, its characteristic is that the servo system's control device is directly operated by the brake pedal mechanism. Its output force acts on the hydraulic master cylinder, pressurizing the master cylinder fluid together with the pedal force. This distinguishes it from the "booster-type" servo braking system—the "booster-type" servo braking system features a brake pedal mechanism controlling the brake master cylinder. The hydraulic pressure output from the master cylinder is transmitted to the auxiliary cylinder and controls the servo system. The servo system's output force and the master cylinder's hydraulic pressure jointly act on the auxiliary cylinder, resulting in the auxiliary cylinder's output to the wheel cylinder being much higher than the master cylinder's hydraulic pressure.
Last time I was on the highway, the steering wheel suddenly became as stiff as a rock, and I almost crashed into the wall. After inspection, it turned out the power steering pump was broken, and the belt had also come loose. This kind of situation is common in hydraulic power steering systems, especially in older cars which are more prone to such issues. The power steering pump is driven by the engine, so if the belt breaks, the pump stops turning, leading to insufficient oil pressure and making the steering wheel heavy. Oil leakage is another major issue; if the power steering fluid reservoir is low or completely empty, the power assist will fail. For cars with electronic systems, motor or sensor failures are more complex and require professional diagnosis. It's extremely dangerous if this happens while driving, so it's advised to pull over immediately and seek help rather than trying to drive through it. For prevention, check the power steering fluid level and belt condition every three months, and have the entire system inspected by a mechanic during maintenance—safety first.
