What Happens When Your Master Cylinder Fails?
Posted on: 18 July 2022
Most people know about the more common braking components, such as brake pads, calipers, and rotors. These parts either wear out over time or tend to fail as a vehicle ages. Whatever the case, there's a good chance you'll end up paying for replacements sooner or later. However, these common items aren't the only components that keep your braking system working safely.
A less prominent, but incredibly vital part of any car's braking system, is the master cylinder. You can think of the master cylinder as the central control center for your car's brakes. When you push down the pedal, the master cylinder transmits that force (via hydraulic pressure) to each wheel. Unfortunately, master cylinders can and occasionally do fail.
What Happens When Your Master Cylinder Fails?
Modern vehicles use "tandem" or "dual" master cylinders. This design divides your car's braking system into separate circuits for the front and rear wheels. A tandem approach drastically increases the safety of your vehicle by removing the potential for a single point of failure. If one circuit experiences a pressure drop, there should still be enough pressure in the other circuit to allow you to stop.
Unfortunately, the master cylinder itself can still fail, and this failure can impact your car's entire braking system. Depending on the failure mode (and how long the problem goes on), you may experience symptoms ranging from relatively minor to severe or even catastrophic. Early symptoms may include a spongy pedal feel or stuck calipers. As the problem progresses, your brakes may fail.
Why Do Master Cylinders Fail?
Like any other part of your car, a master cylinder can eventually fail due to normal wear and tear. A typical modern master cylinder contains two pistons and several seals that help contain the brake fluid. These seals can break down due to heat and age, slowly allowing brake fluid to escape from the reservoirs. Faulty seals can also allow moisture into the cylinder, damaging the pistons or return springs.
While these problems often occur on older vehicles, master cylinder can fail even on cars with relatively low mileage. For example, contaminated brake fluid can cause the internal seals to fail more quickly, causing the cylinder to wear out and leak fluid. As the problem progresses, you will lose more brake fluid and begin to notice changes in your braking behavior.
How Can You Fix the Problem?
There's no way around it: if you can feel your brake pedal becoming soft or spongy, you have a serious problem. Once you notice this symptom, you should stop driving your car as soon as possible and have a qualified technician inspect your braking system.
Contact a local auto shop to learn more about brake repair.
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