Hard Brake Pedal Cause

Have you experienced along your way that your brake has made you so nervous?

Your brake pedal was so hard to press and yet your brake doesn’t grip the brake disk and your vehicle continues to advance.

Hard Brake Pedal Cause-brake pedal


Before anyone starts the journey at least he must have inspected the brake system, meaning the brake fluid level, the brake pads by testing how it grips the brake disks a day before the travel and I usually do this.

But one day I got so nervous that the brakes were not working normally. I assured myself that everything was fine because brake fluid was full, no brake fluid leaks, brake disks were fine. I went on to the whole journey with a very cautious driving thinking of what has been causing the problem.

Thankfully I got home safely. The following day I tried to look into the problem without any knowledge of how a power brake works.  I know what a power brake vacuum booster is but I don’t understand why it is connected to the alternator.

As I look into the tube connected to the power brake booster and onto the alternator I noticed a certain part that joined the two, and it is this small thing below, called check-valve.

Stiff Brake Pedal Causes -Check Valve
Check Valve


Stiff Brake Pedal Causes-power booster vacuum


This is the power brake vacuum booster wherein the hose in the image below is attached.





Stiff Brake Pedal Causes-vacuum tube or hose


This is the power brake vacuum booster hose connected to the alternator.




Stiff Brake Pedal Causes-alternator

This is the alternator that charges the battery when the engine is running.

But it also helps in the brake system. The air produced by the alternator that passes through the hose and goes to the vacuum booster helps create pressure to push the brake piston when you press the brake pedal.

In between the alternator and the brake vacuum booster is the check-valve which is shown below. 

Stiff Brake Pedal Causes-illustration



This power brake check valve connects the power booster and alternator through a hose. In between the hoses, this check-valve is inserted.





Stiff Brake Pedal Causes-Melted check valveOn the images above the check valve is near the power booster but in my car, it is near the alternator. I noticed that this thing has been over the exhaust manifold and it was melted so it cannot function normally.





The video below illustrates the place of the check valve. Please watch.


The check-valve used here in this car model is simple, it looks not like a booster check valve.  You can find different images and see what is used in your car because there are a lot. Check it here.

That made everything about brake system problematic which anyone cannot immediately determine.

It’s good I accidentally noticed it and I learned a lot and that learning is worth-sharing.    






3 thoughts on “Hard Brake Pedal Cause”

  1. Hi this is a great explanation of what in my experience has been a fairly common occurrence if you don’t properly maintain your vehicle. You sound as if you really know what your talking about and I think I will book mark your site for future reference.  I will also be looking at other pages on your site to gain an idea of what else to be aware of with my soon to be new car. Thanks 

  2. This is a great article.  Vehicle safety is so important and if you even get a slight feeling that there is something wrong with your brakes then this is something that needs to get checked immediately.

    Nice thing about newer vehicles is all the sensors usually detect anything that is wrong and gives you a early warning so that you can deal with it.

    Thank you for sharing your experience.  This could actually save someones life.

    • Thank you Dale. Yes, in newer cars you don’t have to worry of what you need to maintain and fix because they are equipped with sensors that tell you about what part is getting defective.

      Please share what you have found here to those who are still using the older models so they will be guided too.


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