Why Are My Mercedes-Benz C-Class Brake Spongy? Tips to Fix Them

Driving your Mercedes-Benz with spongy brake is not just infuriating- it is dangerous. However, they are quite easy to fix. Spongy brake pedals can be caused by any number of reasons and you should be quick to figure out what’s causing this problem in your Mercedes-Benz. In this article, we will discuss some of the most common reasons why brake pedals often get spongy and the way you can deal with them. To begin with, let’s discuss the working principle of car brake.

What’s a braking system and how does it work?

The braking system is a mechanism employed to decelerate a vehicle. To do so, it converts the kinetic energy of the vehicle to thermal or electric energy (in the regenerative braking system). Based on working principle, it is of the following types;

Frictional brakes

Pumping brakes

Electromagnetic brakes

Frictional brake is the most widely used brake and can be found in almost all modern vehicles. It is again divided into two subcategories; drum and disc brakes. Their performance can be regulated hydraulically, mechanically, pneumatically, or electromagnetically.

Mercedes-Benz C-Class employs power-assisted hydraulic disc brakes- which is made up of; disc or rotor, caliper, brake pad, brake line, power brake booster, master cylinder, and pedal. In addition to the above-said parts, hydraulic brakes come with a hydraulic fluid that amplifies and convey the brake force to the rotor in an attempt to decelerate your car.

Now that we know the working principle of Mercedes-Benz C-Class’s braking system, let’s find out some of the most common reasons why they can get spongy and put your safety in jeopardy.

What causes spongy brakes?

Low brake fluid

While there are several reasons why brakes can get spongy- running low on brake fluid is by far the most common cause. The brake fluid is a kind of hydraulic fluid employed to amplify and convey the braking force. It is of four different types; DOT 3, DOT 4, DOT 5, and DOT 5.1.

Factory recommended brake fluid for Mercedes-Benz is DOT four plus. Running low on brake fluid can make your braking system inefficient, resulting in spongy brakes. So, if your Mercedes-Benz brakes feel soft or spongy, the first thing you should do is to check the brake fluid level and if it’s too low, consider replenishing it.

Old or contaminated brake fluid

The brake fluid is the lifeblood of your Mercedes-Benz braking system. Its unique chemistry allows it to amplify and transfer the brake pressure to the front and rear brakes in an attempt to slow down your car. It works because “liquids can’t be compressed”.

However, its hygroscopic property enables it to absorb moisture from the air. The presence of an excess amount of moisture in the brake fluid can limit its ability to do its job, resulting in spongy brakes. Therefore, you should check the brake fluid quality in your Mercedes-Benz daily, and if it’s heavily contaminated consider replacing it.

Worn out components

The braking system is made of numerous parts namely; rotor, caliper, pad, brake line, master cylinder, booster, and pedal. In addition to this, the braking system works in close coordination with the ABS, advanced brake assist, TCS, and other types of safety mechanisms to keep you safe on the road.

Technical flaws in any of the above said parts can make your car brake spongy and soft. It would limit your ability to get control over your vehicle and you might end up in a fatal road accident that might cost you your life.

Is it safe to drive with spongy brakes?

The braking system essentially allows the driver to get full control over the speed of a vehicle. If the braking system of your Mercedes-Benz gets spongy, you might end up in a fatal road accident. Therefore, it’s highly recommended for you to figure out what’s causing this problem so that you can repair it on time.

What to do if your brakes are spongy?

As explained earlier, low or contaminated fluid is the primary reason why brakes often get spongy. Therefore, if your Mercedes-Benz brakes are soft or spongy, the first thing you should do is to check its brake fluid quality and quantity. If necessary flush it.

Endnote

If your Mercedes-Benz brake pedal feels spongy or soft, it signals serious brake trouble. If left unchecked, it would hinder your ability to get control over the speed of your vehicle and you might end up in a deadly collision. Therefore, it is highly recommended for you to figure out the reason why the brakes of your Mercedes are exhibiting such strange behavior so that you can fix it on time.