What are the symptoms of a faulty vacuum booster?
2 Answers
Automotive vacuum booster pump failure symptoms: It can cause heavy steering and abnormal steering noise. The larger the steering angle at low speeds, the louder the noise. Worn metal particles from the booster pump can damage the steering gear, and cleaning the pipelines is also troublesome, potentially requiring replacement. Additional information: 1. Definition of booster pump: An automotive booster pump refers to a component that helps improve and stabilize vehicle performance. It mainly assists the driver in adjusting the car's direction. Currently, most vehicles are equipped with booster pumps, primarily including steering booster pumps and brake vacuum booster pumps. 2. Classification of booster pumps: In the current market, power steering systems can be roughly divided into three categories: mechanical hydraulic power steering systems, electro-hydraulic power steering systems, and electric power steering systems. In mechanical hydraulic power steering systems, the amount of assistance is only related to the increment in steering wheel angle (angular velocity).
When the vacuum booster fails, the main symptom is that the brake pedal becomes extremely stiff and heavy, requiring significant effort to press, as if you're using brute force, with none of the usual smooth assistance. I experienced this while driving—normally, a light tap on the brake would stop the car, but suddenly, I had to stomp on it with all my might, nearly rear-ending the car in front. It was terrifying. Additionally, the braking distance noticeably increases; where it used to take 5-6 meters to stop, now it takes 7-8 meters, making it especially dangerous. Another sign is a hissing air leakage sound when pressing the brakes while the engine is running, as if air is escaping somewhere. This is no minor issue, as a faulty booster compromises the entire braking system, drastically reducing driving safety. You should immediately take it to a repair shop—it’s likely due to aging vacuum hoses or seal failure. During the inspection, have the mechanic test the pedal stiffness to prevent it from escalating into a major problem.
