My Brake Pedal is Stiff and Car Won’t Start: Diagnosing the Problem

As an Amazon Associate, I earn from qualifying purchases.

What if you are driving smoothly but suddenly the brake pedal gets stiff or hard to press? Brake is important, and functioning it right is needed to avoid risks. Over time, there are some problems with brakes that cause many problems. One of them is the brake pedal is stiff or hard and the car won’t start. So why is your pedal stiff and the car won’t start? 

The problem occurs for various reasons. The most typical reasons are faulty brake boosters, malfunctioning vacuum pump, broken vacuum hose, seized or jammed caliper, damaged ignition switch, etc. This is not the end. There are more culprits behind this hassle.

If you want to know more and eliminate this hassle in no time, read this article thoroughly. Here I’ll discuss every possible reason with a simple solution to make resolving effortless.

Uncovering the Causes of a Stiff Brake Pedal

Knowing the exact reasons for the problem (locked up brake pedal) is mandatory to resolve it effortlessly. Without understanding the reasons, it’s almost impossible to fix the issues. So check the table below to get a quick view.

Possible reasonsPossible Solution
Vacuum leak on the master cylinder lineSeal the hole tightly or replace the vacuum line immediately.
Low-power steering fluidBoost ups power steering fluid by inserting more fluid as per requirement.
Broken vacuum hose or lineChange the vacuum hose or line.
Jammed or seized caliperLubricate the brake system properly to eliminate this issue.
Dirty brake linesClean the brake lines by using non-residue brake cleaners.
Exhausted brake vacuumLeave the brakes for a while and start the car again.
Ignition switch failureReplace the ignition switch.
Worn-out starter cableChange the starter cable as soon as possible.
Damaged batteryReplace the battery.
Gasket leakMend the leak or change the entire gasket 
Brake draggingReplace the return spring or retracting springs

Now is the time to elaborate on the discussion for your convenience. Here is a detailed explanation of these reasons and how to avoid them.

Vacuum Leak On The Master Cylinder Line

When you notice or experience the car brake pedal is hard to press, first, check the vacuum on the master cylinder. Over time, the master cylinder vacuum leakage creates this issue. The brake booster always works excellently to maintain vacuum pressure.

It is linked directly to the intake manifold of the engine through a vacuum line or hose. When the brake booster malfunctions or becomes damaged, it fails to create a vacuum, and the master cylinder does not receive power.

Solutions: Admit it, the brake is an essential component of any vehicle, and the other brake-related parts are as well. So fixing the issues immediately is required. When you are sure your brake booster is leaking or getting damaged, you may need to replace the master cylinder.

Low Power Steering Fluid

You’ll face trouble pressing the brake pedal if there is low-power steering fluid. But how do you know that you have low steering fluid? The first thing you should check is whether the steering wheel is going right or not. Other reasons include turning the wheel seems challenging, loud steering, sludge or stains under the vehicle, weird noises (squealing noises), fluid leaking, steering wheel jerking or vibrating, shrill steering, etc.

Solutions: When the fluid is too low, this problem occurs the most. So it’s better to insert the fluid. Also, you can check the bearing, power steering pump, or worn seals. Replace worn seals or change the power steering pump.

Broken Vacuum Hose Or Line

Do you notice your engine running roughly or the check engine light appears on the dashboard? Understand there is a leak or broken vacuum hose. If this happens, your brake pedal will stiff and not allow you to press smoothly when a serious situation comes.

You’ll sometimes face lots of trouble, even severe accidents. Also, when the vacuum hose gets damaged, the engine fails to supply power or won’t start, the engine backfires, wired sounds from the vacuum, etc. If any of them happen, you must fix the leak soon. Otherwise, it’s not far away you’re destroying yourself and your car as well.

Solutions: Seal the Vacuum leak with a ¼” connector. Just put the connector into the hose. Make sure you hear a sound like “Click.” Otherwise, you can change the vacuum hose or get in touch with an expert.

Jammed Or Seized Caliper

Another intriguing cause for brake pedal stiffening is a jammed or seized caliper. The common symptoms of bad calipers are fluid leaks from the brakes and unwanted sounds (grinding) while driving. In addition, difficulty gaining momentum, pulling the vehicle to one side, activating brakes while running, coming smoke from wheels, slowing down quickly automatically, etc. are also happening for this problem.

So if you notice any of these troubles and your brake pedal is stiff, understand the caliper is damaged.

Possible Solutions: You can replace the brake caliper or repair it. Repair it with a qualified mechanic.

Dirty Brake Lines

Dirty brake hoses or lines could be the main culprit for why the brake pedal is hard to press. Contamination on the brake lines or brake fluid can hamper the brake from pressing smoothly. It causes the brake to lock up and increases the stopping distance.

The Brake system, especially the hydraulic brake unit is sensitive to pollution or contamination. If the brake fluid is dirty or contaminated, you feel the brake is sticky to perform. Also, a corrosive brake system is another concerning issue if the brake pedal is sticky or stiff.

Possible Solutions: Change the old fluid and insert the new one. If the brake lines are messy, clean them thoroughly with aerosol or other suitable cleaners.

Exhausted Brake Vacuum

Most modern automobiles feature power assist to make the operation easier. It relies on the vacuum to operate smoothly. But when you push down the brake pedal without starting the engine, it exhausts the existing vacuum when the car is off. If this happens, you notice your brake pedal going stiff.

Possible Solutions: Leave the brake for a while and start your car. The brakes will return to normal once power assistance is provided if there is a problem with the brake vacuum.

Ignition Switch Failure

This symptom is mostly applicable to older vehicles. If you owned an earlier generation or model car, check the ignition switch after facing trouble with the brake pedal stiffening. You’ll notice the flickering lights on the dashboard, the cranking sound from the engine, the engine starting delay, the car stalling, etc.

Possible Solutions: First, check whether the ignition switch still works or not by a multimeter test. If you find any issues, change the ignition switch by yourself or a mechanic.

Disconnected Starter Cable

Another reason for your brake pedal to go stiff is a faulty starter cable. Often, this problem happens when the starter cable, however, gets deviated from the battery terminal. The most common symptom of a faulty starter cable is loud clicking sounds after turning the key ON.

Possible Solutions: Connect the starter cable to the battery. This task is done by yourself if you have enough knowledge. Otherwise, hire an expert to deal with this problem.

Damaged Battery

If the car battery is worn out or damaged, the entire function will go in vain. The battery is a critical part of any car. When the battery is damaged, you’ll face lots of troubles, including brake pedal stiffness. In addition, you’ll face difficulty in starting the car, illuminated interior and dashboard lights, sluggish start, weird noises, etc.

Possible Solutions: When you notice bad battery symptoms, repair it immediately. Otherwise, change the battery entirely.

 Gasket Leak

A leaking gasket is a concerning issue for every car owner. You can’t drive smoothly with a leaking gasket. The common symptoms of a leaking gasket are coolant puddles underneath the vehicle, the lean coolant level in the reservoir, a bad smell from car vents, white smoke coming from the exhaust, etc.

So these are not the simple issues that you ignore. After experiencing problems like these, take immediate steps to fix them.

Possible Solutions: The repairing of gasket leaking is straightforward. Simply take off the leaky gasket and replace it with a new one. If you’re unable to do it, hire an expert to get the job done.


Can Dirty Brake Fluid Cause Brakes Stick?

Dirty brake fluid can be a major culprit behind your car brake pedal being stiff. Contaminated brake calipers can’t perform the way clean calipers do. Old brake fluid causes corrosion to the brake calipers, causing the hard-to-press brake pedal problem.

What Can Cause An Extremely Hard Brake Pedal?

There are lots of reasons that resist brake pedals to work excellently. Among them, the most common culprits that cause extremely hard brake pedals are malfunctioning brake pedals, power steering fluid flow, and a broken vacuum hose.


So there is the end of the guide about why your brake pedal is stiff and the car won’t start. The brake is the most crucial part of any vehicle to drive safely. But when the brake pedal gets jammed or hard to press, you can’t enjoy smooth driving, let alone go for a long drive. There are several reasons why your brake pedal goes stiff and the car won’t start. The most common reason behind this is a faulty brake booster. Luckily, there are handy solutions to eliminate this hassle. Hopefully, you have now known the possible reasons with solutions.

More resources:

Leave a Comment