Brake Pedal Feels Soft – Why Is This Happening?December 24, 2023
Have you noticed how the brake pedal feels soft and spongy and you wonder why is this the case? Well, if that’s correct, you are in the right place because, in this article, there will be a lot to cover when it comes to the problem when the brake pedal feels soft.
Doing your own research is always a good idea when it comes to car problems. Sometimes good research will give you the right input and will help you tackle the problem cheaply and effectively. This is why we are here to help you out with that.
First, we are going to elaborate more on the problem when the brake feels soft. Then, we are going to cover all the possible causes of this problem and also how to solve it. So, without further ado, let’s dive into the article.
Brake Pedal Feels Soft – The Problem
Now let’s elaborate more on the problem when the brake pedal feels soft and spongy. When and how this problem happen?
Well, this problem can happen after maintenance is done to the brakes or randomly while you drive.
This problem is very random and it does not show any previous symptoms, except for brake fluid leaks.
If you notice that there is a leak on the side of the tires and these leaks are often slightly greasy and lack any coloring, this is definitely brake fluid.
Shock absorbers or struts can also leak on the sidewall, but they have red hydraulic fluid that is easy to notice. And these leaks will also have no effect on the brake pedal as in this case.
So, the final conclusion is that this problem when the brake pedal feels spongy can happen all of a sudden and is very random.
The important thing in this case is not to ignore the problem and you should work hard to tackle it.
We are saying this because these are the brakes and brakes should be functional 100% of the time. If they are not, your car will not stop and you will crash!
Why Brake Pedal Feels Soft? All The Possible Causes!
Now let’s take a look at the possible causes of why the brake pedal feels soft and squishy. What are the possibilities behind this problem?
1. Air In Brake Lines
In most of the cases, this problem is caused by air in the brake lines. So, why is this the case, how come air can cause such a problem?
Well, brake fluid is a fluid that is not compressible. It is quite similar to hydraulic fluid but a bit thinner.
While air is compressible. You’ve probably heard about compressed air. So, by this logic, air can compress.
And when you press the brake pedal and the pedal feels like a sponge, you compress the air in the process.
There is simply not enough pressure in the lines for the pedal to be firm. That’s why it is soft and squishy.
This is why you should always connect this problem with air in the brake lines. The rest of the causes that we will list are only the outcomes of how this air enters the brake lines and causes this brake pedal softness.
2. Damaged Brake Lines
The second most common cause for the case, when the brake lines feel soft, is the case when you have damaged brake lines.
There are many brake lines that go from the ABS and master cylinder to the calipers. Sometimes these lines can corrode and start to fail.
This is a common thing on older cars that do not have very advanced brake systems. Build quality was very poor back in the day.
So, the lines are often attacked by rust issues. The fittings can also fail and allow air to go into the lines.
This is why we often advise inspecting all of the brake lines and fittings for leaks. Since this can be causing your issue.
3. Bad Brake Caliper
A bad brake caliper can also make you notice how the brake pedal feels soft. The brake calipers are the components that squeeze the pads and make them contact the rotors so your car stops.
These calipers have something known as a piston. The piston is a movable component that is not visible when the rotor assembly is mounted.
This piston moves in and out of its housing when you press and depress the brake pedal.
In many cases, these pistons fail. Specifically, the rubber that is used to mount them on the caliper.
Once this happens, you will have air into the brake lines since the seals are not sealing properly.
This is why we advise that you refurbish or replace the caliper if this is causing the problem with your vehicle.
4. Bad Wheel Cylinder
If your car is using drum brakes on the front or on the rear, this could also cause a problem.
If you look at the drum brake assembly, you will notice a component known as a wheel cylinder.
This component works with the help of hydraulic fluid. This wheel cylinder is located at the top of the assembly.
The wheel cylinder simply opens and closes and expands and contracts the brake shoes, so your car comes to a stop.
These wheel cylinders can also leak and allow air to enter the brake lines and cause problems with the braking capability of your vehicle.
The car will not like to stop well and you will have a problem. So, if you have an old car with drum brakes, we recommend refurbishing the brakes and replacing these wheel cylinders with new ones.
Now let’s move on to the next causes for the brake pedal feels soft problem.
5. Bad Master Cylinder
The master cylinder is another very common cause for soft brake pedal. So, what is the master cylinder?
Well, the master cylinder is the brain of your braking system. This component is mounted on the firewall.
This is the component that has a brake fluid canister where you top off the brake fluid. This brake master cylinder is a very simple component that does all the heavy lifting in creating strong pressure in the brake lines.
And as with every other component in your car, this brake master cylinder can fail and cause your brakes to lose pressure. Which will result in a soft brake pedal.
Usually, a tell-tale sign of a failing master cylinder can include visible leaks around the master cylinder.
But this isn’t always the case since this component can also fail internally.
So, if there are no leaks in the system, you should definitely consider checking the master cylinder itself and see if this component causes the problem when the brake pedal feels soft.
How To Diagnose Fix The Soft Brake Pedal?
Diagnosing and fixing this problem can be somewhat complicated since you need to inspect the brake lines.
So, the car needs to be lifted on a lift or on jack stands in order for you to be able to inspect the vehicle.
This is why we recommend that you visit a shop for this job and let the technician solve the problem for you.
Once the problem is found, they will simply replace the line, fitting, or brake caliper piston. Remove the air and the brake pedal will be as good as new once again.
Cost To Fix The Soft Brake Pedal
The cost to fix the problem when the brake pedal feels soft can vary from $50 to $300. But in general, it is fairly cheap to do this job.
This is the case because there are no major mechanical overhauls, none of that when it comes to this problem.
If a mechanic is experienced and knows how these brake systems work, he should be able to tackle this problem in no time.
In this article, we covered quite a bit when it comes to the problem when the brake pedal feels soft. First, we elaborated on the problem, and in the second part, we covered all of the possible causes that can be causing this issue to you.
Lastly, we discussed the common diagnostic methods and overall how this problem is tackled. Overall, not a serious issue that is often caused by a little air in the system that needs to be removed and the brake pedal should be nice and firm once again.