4 Bad Brake Booster Symptoms and How to Solve These Problems

Hi, Welcome to Right To Rise SuperPac, Here is another technical post for your vehicle.

Technology has been advancing over the years adding more convenience to our lives. This becomes applicable even for the devices and machines that we use.

Gone are the days of three-wheeled vehicles powered by gasoline. Today, we have vehicles fitted with enhanced features to add comfort, entertainment, and innovation to our journeys.

However, a lot of these innovations are not so obvious.

When you look at a new vehicle in a showroom, you check out its interiors, its features and perhaps even its power.

But there is more that goes into a vehicle. Some of them are not noticeable instantly.

Like for example, a brake booster.

Similar to every other part of the vehicle, a brake booster can go bad. When it does, you should be aware about how to solve the problem and prevent the condition from getting worse.

4 Common Symptoms of a Bad Brake Booster

As we had mentioned before, a brake booster is merely another part of the vehicle. This subjects it to some conditions that might prove unsafe for your driving. Treating them at the earliest stage possible will prevent accidents from occurring, potentially saving your life.

Now before we head over to solving the problems, let us find out just what these problems are.

1. Hard Brake Pedal

One of the main instances that show a bad brake booster is a hard brake pedal. This happens when the brake pedal becomes really hard to push.

This problem may occur gradually over time or it may present itself instantly. Sometimes, the brake pedal will refuse to return to its initial position after being pressed. But if you are wondering why a hard brake pedal even occurs in the first place, then we have the reason for you.

You see, there are quite a few scenarios that can cause a rather stiff pedal. One of the primary reasons is the absence of enough vacuum.

You can typically compare an engine to a pump. The mechanism takes in the vacuum and provides it to the brake booster through a part known as the vacuum hose.

The vacuum works alongside atmospheric pressure to ensure that the entire brake booster is functioning properly and your brake system is in top performance condition.

However, sometimes there is an imbalance between the vacuum and the atmospheric pressure. Because of this, the diaphragm does not move as properly as it used to.

You will then have to apply pressure manually using your foot to make the diaphragm function adding much resistance to the entire process. This causes stiffness in the brake pedal, and you have a hard brake problem.

In other scenarios, there could be a problem within the valve of the brake booster. A lot of people often don't pay attention to this until the moment it becomes a serious problem.

The vacuum hose is attached to the brake booster via a circular valve. When creating the vacuum within the engine, the valve becomes the component that regulates the flow of vacuum.

When the valve stops functioning well, this flow is often disrupted; lending less vacuum than necessary.

2. Braking Distance Is Long

If you apply your brakes and the vehicle takes a long to actually come to a halt, then you have a problem with the brake booster.

The main reason for this is that your vehicle is not providing enough power to brake efficiently.

This becomes harmful for a lot of reasons;

  • In case of emergencies, you cannot rely on the brake system. When this happens, you can enter into fatal accidents causing massive damage to both vehicle and person.
  • When you are driving in harsh conditions such as a snowstorm, you will need a proper braking mechanism. A failure in the system causes you to careen off the road.

3. Booster Locks After Being Replaced

People have often noticed that their brake boosters lock-up after they get replaced. This leads to an ineffective brake mechanism causing you to experience some dangerous situations best not encountered.

4. Engine Problems

We have earlier mentioned that the brake booster includes a diaphragm. Now, what happens if faults and issues affect the diaphragm itself?

When such a situation occurs, you will begin to notice that your engine will stall when you hit the brakes. Now, this is not just an issue of the braking system, but the entire engine itself.

This causes problems for the engine in the long run which only leads to either an expensive repair or an extremely dangerous situation.

Testing the Brake Booster

Now that we have discussed some of the common problems of a brake booster, let us find out how to solve them.

Before that, it is time to test your brake booster.

Most of the vehicles that are manufactured today come with the vacuum system. This makes it easy for you to test out the booster at your home. You can do this in a few simple steps.

Method 1

  • Ensure that the engine is off before you try to test anything. Having confirmed that, begin pumping the brakes. You should do this about five or six times. When you do this, the engine exhausts the vacuum stored inside the brake booster.
  • Now, place your feet on the brake pedal and press down lightly. While doing that, turn on the engine. If your brake booster has no issue whatsoever, the pedal will depress a little, but then become firm. This indicates an efficient brake booster.
  • On the other hand, if there is a problem with your brake booster, the pedal will not become firm. Turn on the engine while keeping your foot still depressed on the pedal. If you notice that the pedal is pushing back against your foot, then you definitely have a problem with the booster.

Method 2

For this method, you should keep the engine running for a while before switching it off completely. Once you have switched it off, you can begin pumping the brakes a few times.

You will notice that initially, it will be easier to push the brakes. As you keep pushing, it becomes harder and harder to do so. If that is the case, then your brake booster is just fine.

However, if you do not see this change in resistance, then your brake booster might have a leakage problem.

Method 3

Once again, we will turn on the engine in this method. However, we will not switch it off later. Hence, keep the engine running for a while before you go over to the next step.

Push on the brake pedal slightly and keep the pedal in this position. The brake should be able to stay in this position without having any shifts if should not start going lower.

If it doesn’t, then your brake booster has no problem. However, if it gradually begins to go low, then your brake booster might be faulty.

How to Solve Brake Booster Problems?

Now that we have explained some of the problems of a brake booster, and shown you how to discover if there are any problems, let us show you some common solutions for them.

Change The Check Valve

First, locate the spot where the brake booster connects with the vacuum line. At this particular spot, you will spot the check valve.

After that, check and see where the clamps of the check valve are assembled. By taking great care, remove these clamps. Once done, remove the valve line.

Finally, remove the check valve using an appropriate tool such as a wrench or a screwdriver. Ensure that you have the right size for the wrench and screwdriver.

Get the new check valve and fix it correctly in the spot that the old valve was resting. Reattach the vacuum hose and all other parts.

Ensure that you secure each part firmly so that they do not come off while you are driving, leading to serious accidents.

Replace The Brake Booster

Replace The Brake Booster

To easily spot the brake booster, know that the master cylinder will be found in front of the booster.

Try to find out what type of clamps hold the booster down. Once you have identified that, you can remove them from the vacuum line.

Next, ensure that you remove the master cylinder as well. Use the appropriate wrench to make quick work of this task.

Then you have to begin working on the brake pedal. Separate the restraining bolts on the pedal.

Finally, you are ready to replace the brake booster. Find out some high-quality boosters on the market. Place the new booster and then the master cylinder.

Put together the previous parts in the reverse order of removing them. Make sure that each part is secured firmly before moving on to the next component.

Replace the faulty brake booster

In case of the problem where your vehicle takes longer to stop after the brake has been applied, you might want to change the entire brake booster.

At this point, it is essential to make the change as soon as possible. Failing to do so might cause wear on the other components of the vehicle, allowing you to replace more parts in the future.

Brake Booster Replacement Cost

The cost of a brake booster is often between $150 and $600. It all depends on the type and quality of the product. However, this cost will escalate once you add the price of the labor, which goes from $120 to $200, depending on the model of the car and the type of brake system you have.

Before doing anything though, ask a mechanic or expert to know whether you can fix the problem with penetrating oil like the WD-40 or PB Blaster. This will help you possibly avoid wasting the money that you could use for more productive things.

Brake Booster Options

Now that you have figured out some of the steps involved in changing the brake booster, let us give you a few options of brake boosters, in case you are planning on replacing the part entirely.

1. Mazda TDY1-43-80ZA Power Brake Booster

The best thing about this brake booster is that it is an original factory part, meaning it is actually manufactured by Mazda itself. That gives you a lot of comfort about its quality.

The price point on this part is not too expensive as well. You get a good quality product that has got some good reviews in the market.

However, do check if this fits the make and model of your vehicle. Sometimes, it could fit in one model of a car but might not attach itself into another, more recent and older model.

2. Cardone 53-2510 Remanufactured Import Power Brake Booster         

While this brand is not well-known in the brake booster areas, the product itself shows some high-quality use.

The part is manufactured in such a way as to focus on reducing wastage. The product has been vacuum tested as well so that it can run for a long period of time.

Consider this if you are looking to restore normal pedal pressure or if your pedal is gaining some rust.


Never let the problem become severe before dealing with it. React soon and get the brake booster replaced or fixed before it can do further harm.

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