Brake Pedal Goes to Floor When Engine Running – Causes & Solutions

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Brake pedal goes to the floor when engine running is nightmares for any driver. This is not only the worst moment but also very dangerous. Because brakes are one of the most significant safety features of your car. 

So, when you face any difficulty in the car’s braking system, you have to find out the problem.

In this article, we discuss the causes of the brake pedal going to the floor when the engine is running. Along with, we’ll talk about all of the possible solutions to solve this problem.

Causes Of Brake Pedal Goes to Floor When Engine Running

Brake pedal goes to the floor when the engine is running can cause different number problems. Here we discuss the most common reason you’ll have to face. The major problems are as follows:

brake pedal goes to floor when engine running

      1. Loss of Brake Fluid

One of the main reasons brake pedals go to the floor when engine running is a loss of brake fluid. The brake fluid maintains the pressure that delivers the braking power to the brake pads on the wheels. 

Any cracks or holes on the brake fluid line can break out the brake fluid. The result is, when you press the brake pedal, no pressure will be delivered. So, if you’re losing brake fluid, your car will lose a large amount of fluid that’s required for braking pressure. 

Hopefully, this is very easy to diagnose, you can simply see brake fluid underneath your car. If you find any leaks in the brake fluid line, you have to seal the cracks or holes to solve this situation. But if you didn’t find leaks in the brake fluid line but your brake pedal goes to the floor, there can be leakage in the master cylinder or brake booster.

     2. Bad Brake Master Cylinder

A bad brake master cylinder is another major reason the brake pedal goes to the floor when the engine is running. This is where brake fluid gets compressed and it’s rubber seals prevent the brake fluid from leaking out. If these seals are old, damaged or worn out, they will leak or let the brake fluid go out. Once your master cylinder isn’t working properly or works only occasionally, braking pressure is reduced or going worse. You have to lose braking power as a result of your brake pedal going to the floor. So, this cylinder has to be sealed completely so that it can retain the required braking pressure. 

Strictly speaking, there are two main reasons why your brake pedal goes to the floor: 

  • Brake Fluid Leaks.
  • Malfunctioning Master Cylinder. 

In many cases, these two reasons are not exactly not responsible. Further, there are other reasons that you also have to be on the lookout of. So, let’s talk about all other possible reasons one by one.

     3. Bad Brake Booster

Bad Brake Booster

The brake booster is placed between the brake pedal and master cylinder and connected to the engine. You don’t have to put much foot pressure on the brake pedal to stop the car.

But, once the brake booster is bad, you have to suffer to stop your car. Because you don’t get the enough power that’s needed to stop the car. So, a bad brake booster is another 

the reason your brake pedal goes to the floor.

  1. Air in Brake Lines

Sometimes the brake pedal goes to the floor after replacing the new master cylinder. Many drivers have experienced this kind of problem. This occurs when no air bleeding is done after installing a new master cylinder, and consequently, there is air in the brake lines. This air prevents the efficient brake flow inside the brake line, damages the brake lines and gives a spongy soft feel. Ultimately,

This will bring damage to the brake line.

  1. Style of Driving

It sounds crazy, but there’s one more thing that causes the brake pedal to go to the floor: you, the driver. Your driving style will be the reason the brake pedal goes to the floor when you stop your car. But, how?

The more you use your brake, your brake fluid becomes hotter. Hot makes the brake fluid thinner. Thinner brake fluid delivers lesser efficiency for braking pressure. So, your braking system will not get the required power.

Solutions Of Brake Pedal Goes to Floor When Engine Running

Hopefully, this problem is easy to diagnose and very simple to solve. Because it doesn’t include any parts of the car braking system. You just have to find out the problem and accordingly go to the solution.

  1. Check Brake Fluid Level 

First of all, you have to check the brake fluid level as the main reason for this problem is leaking brake lines. So, check the brake fluid level and if it’s below than normal, you have a possibility of leakage.

Make a visual inspection on four-wheel to find any oil residue on it due to leakage. Again, inspect the brake fluid lines to detect whether any leak is here or not. You can solve this by replacing the defective part and then fill up the brake fluid level. 

  1. Check the Brake Lines

The next step is to completely check out the brake lines. Inspect your car’s wheels and examine them to find out any oil residues.

car jack

You can use a cross wrench and car jack to detach the tires to do this. Then observe the lines and if you find any oil residues in the brake fluid line, obviously a leak happens. Oppositely, if there’s any damage to the line but fresh brake fluid is present, you have to replace the brake fluid lines either yourself or by a mechanic.

  1. Check the Brake Calipers

Similarly, you have to remove the wheels to check the brake calipers. Likewise, check out to find fluid residues or fresh brake fluids around the brake calipers. If you aren’t an expert in car repair, you have to take the help of a certified car mechanic to examine and replace parts.

  1. Check the Brake Master Cylinder

Lastly, you have to check out the brake master cylinder. Brake master cylinder was sealed inside that prevents brake fluid from outing. Sometimes, these seals wear out and result in the brake fluid to leak. 

Brake master cylinder is an essential part of your car’s braking system. So, it’s necessary to replace a new brake master cylinder.

It’s a job for a professional mechanic, but you can also do this job.

How Much Does It Cost To Repair

Honestly, the repair cost will depend on the problem and how simply or hardly it will be completed. On average, the repair cost of a brake master cylinder is from $200 to $300.

It can take extra depending on the scope of the solution. 

 

But, the most expensive thing occurs when your car needs a whole brake job. The total repair cost will go up to $750 or even more. So, regularly check your car’s braking system to prevent such kinds of repair costs.

Whenever you find any problems in your car’s braking system, you have to avoid driving because it’s unsafe. Primitively, detect the problem and then take action to solve it. If you haven’t the ability to finish the repairs, just consult a certified mechanic. He has experience as well as all of the tools to do the task properly.

Final Verdict

Any difficulty in the brake system is related to your safety. The action for resolving this problem is taking a proper diagnosis. Once you identify the problem then go through the repairs process. You can ask a professional to solve the problem when you are confused.

Whenever you find any problems in your car’s braking system, you have to avoid driving because it’s unsafe. Primitively, detect the problem and then take action to solve it. If you haven’t the ability to finish the repairs, just consult a certified mechanic. He has experience as well as all of the tools to do the task properly. 

If you still have any issues, then ask us in the comment box. 

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