What Causes the Brake Pump to Fail?
3 Answers
The reasons for brake pump failure are as follows: 1. The brake wheel cylinder is not a wear-prone component; its failure is usually due to quality issues. Dirty brake fluid can clog the brake lines, causing excessive pressure in the master cylinder, rendering the brakes ineffective and making the pump prone to damage. 2. Damage to the wheel cylinder is related to not replacing the brake discs and pads in time. When the brake discs and pads wear to their limits, continued use can lead to wheel cylinder damage. 3. Low-quality or aged brake fluid can corrode the sealing cups in the master cylinder, resulting in poor sealing, inability to maintain oil pressure, and subsequent pump damage. Here is some additional information about brake pumps: 1. The principle of car braking is friction. All cars use durable brake pads that press tightly against the rotating parts of the car, using friction to bring them to a stop. 2. The braking systems used in cars can be divided into two types: hydraulic braking systems and pneumatic braking systems. 3. The working principle of a hydraulic braking system is based on the physics concept that 'pressure is equal throughout a liquid.' It uses a sealed pipeline connected to a hydraulic pump. When the master cylinder applies pressure to the brake fluid, the incompressible liquid transmits the pressure to the wheel cylinders, causing the two pistons inside the wheel cylinders to extend outward under the liquid pressure, pushing the brake pads against the brake discs to generate braking force. Therefore, hydraulic pumps are essential in hydraulic braking systems.
There are quite a few reasons why a brake master cylinder can fail, and I was really nervous when I encountered it before. The main cause could be aging and wear—like my old car, which was almost ten years old, the rubber seals inside the brake master cylinder tend to dry out, crack, and leak oil. Another issue is not changing the brake fluid for a long time, allowing moisture or contaminants to accumulate inside, corroding internal components. Driving habits also play a role—for example, frequent hard braking can cause the cylinder to overheat. External factors like rainwater or dust entering the system can also accelerate damage. The most frustrating part is that when it fails, it affects the entire braking system, making the brakes feel spongy or even causing them to fail, which is extremely dangerous for safety. I recommend checking the brake fluid color and level during every maintenance service and addressing any issues promptly—don’t wait until you’re stranded on the road like I did.
In vehicle repair work, there are only a few common root causes of brake pump failures. One is fluid contamination - if owners don't change brake fluid periodically, water ingress or dust mixing can corrode the pump cylinder or pistons. Another is material issues, like aging or cracked seals causing oil leaks that reduce hydraulic pressure. Improper operation also plays a role, such as sudden braking causing overheating wear. More seriously, related component failures like vacuum booster pump malfunction can impose extra load on the master cylinder. These problems all lead to spongy brake feel or even complete braking failure. I typically recommend regular system flushing and fluid replacement, advising immediate inspection upon noticing abnormal noises or pedal feel changes to prevent roadside emergencies.
