My car started shaking and my brake pedal is hard after installing a sound system

My car started shaking and my brake pedal is hard after I installed a sound system what's going on?

My car has 74000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi there. Unfortunately, installing aftermarket electrical components on newer vehicles, can cause major electrical problems if not done correctly. It is possible that during the installation, you may have created an electrical fault, causing some system sensors to either brake or store an electrical warning code in the ECU. This is quite probable if the battery was not disconnected during your stereo installation. Since we don’t offer repairs or maintenance on aftermarket parts or installs, I would recommend contacting a professional mechanic in your area to help you resolve this problem.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

The most common reasons a Toyota Camry shakes when braking are bad brake rotors, bad brake pads, or a bad wheel bearing.
Brake Calipers are Sticking

If the caliper or caliper pistons become stuck, it is unable to properly squeeze the brake pads against the rotors, which may cause you to feel some vibrations when you hit the brakes. Calipers may also get stuck while engaged, which won`t allow the brake pad to let off the rotor.

If you have a stiff brake pedal and the vehicle has a vacuum pump or hydraulic brake booster, some common issues could be a missing serpentine belt, a failing electric pump, or low power steering fluid.
If your vehicle vibrates when you brake, that`s a pretty good indicator that you should have the brakes looked at. The most likely reason for your steering wheel shake is warped brake rotors. When a driver pushes down on the brake pedal, the brake pads squeeze the brake rotors to stop your vehicle.
A stuck brake caliper can also cause brake vibration. The caliper is the device that the brake pads are attached to, and a caliper pushes the brake pads to take hold of the rotors when you apply the brakes. Calipers can get stuck and when they do, you`ll experience shaking or a powerful pull to one side or the other.
1) Your pedal vibrated because the ABS (anti-lock braking system) was activated. If the pedal vibrations (pulsing and groaning noises, too) happened when you e-braked, chances are ABS was activated. ABS prevents your tyres from locking up, which could lead to an uncontrollable skid.
The biggest reason for this shaking problem is the condition of your rotors – the disc your brake pad clamps down on when you apply your brakes. Most commonly, the vibration happens because the rotors have some kind of imperfection on their surface or they have changed shape (warped) over time.
If air gets into a brake line, it can produce uneven pressure across the brake calipers and pads, which could make the car shake when you apply the brakes.
The reservoir should have a label that says, “full line.” If the brake liquid falls below that line, it`s a sign your need to change your brake fluid or top it off. Low brake fluid can also indicate your brake pads are wearing down and need maintenance.
The Shaking is Your Brake Calipers Sticking

The fluid creates hydraulic pressure which forces the caliper to press the pads. If you feel the vibration only in the steering wheel, it could be the calipers sticking and failing to press the pads against the rotors.

The Brake Rotors Are Warped

Excessive heat from braking can warp the rotors, causing the brake pads to slip and a subsequent quivering sensation, most likely in the brake pedal. Generally, your brake rotors should be replaced after 70,000 miles, but this can vary based on driving conditions.

Low Brake Fluid

If the brake fluid level is low, it can reduce the hydraulic pressure in the brake system, causing the brake pedal to feel spongy or soft, and the car to shake or vibrate when you apply the brakes.

While it is uncommon, brake calipers can become seized (also called “sticky” or “stuck”). Seized brake calipers can cause handling trouble—often with steering wheel shaking or pulling. Unlike warped rotors, you will notice this issue when you drive rather than when you brake.
The ABS system works in tandem with the rest of the braking system to stop your vehicle quickly under hard braking. A faulty ABS wheel speed sensor can lead to longer braking distances under those situations.
If your rotors are faulty, they may produce a squeaking, squealing, or grinding sound when you apply the brakes. Warped rotors usually emit a high-pitched squeak, while severely worn rotors tend to make a scraping noise.
Brake shudder (also known as brake judder) is the vibration felt through the steering wheel and suspension when the brakes are applied at certain speeds and pressures. It can vary from a barely noticeable vibration to a violent judder – experienced through either the brake pedal or steering wheel.
Because the CV Axle joints are located right next to the vehicle`s wheels, any damage to them can directly affect your driving. If you suddenly feel as though your vehicle is vibrating more than normal, it can mean that you have a damaged halfshaft.
Is Your Car Shaking After New Tires? If you recently bought new wheels and tires, then your vehicle shaking could be caused by the tires not being balanced correctly. Balancing the tires makes sure the weight of the tires and wheels are evenly distributed for the smoothest drive possible.
Toyota recommends that you change your brake fluid about every two years or 20,000 miles, although no two drivers are the same, and some may require their fluid to be changed more or less often.
Can You Just Add Brake Fluid to Your Car? Simply said, yes. Although you can take your car to an experienced mechanic to do it for you, this is something you can do on your own without too much hassle.
Strange noise when pedaling: When the braking fluid is low, you may start to hear noises when you apply brakes. This is often caused by increased friction in the system. When you hear these sounds, you should have the braking system checked as soon as possible before additional damage occurs.
When your brake fluid is dirty or low, it isn`t able to depress your brake pads as efficiently as it should. This can cause uneven wear or even damage to your brake pads, which can cause grinding, squeaking, or squealing noises when you use your brakes.
Vacuum – or really lack of vacuum pressure – is the most common cause of a hard brake pedal, and therefore the first thing to look at when a hard pedal is present. Any brake booster (whether from Master Power or any other supplier) needs a vacuum source to operate.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car started shaking and my brake pedal is hard after installing a sound system
ANSWER : Hi there. Unfortunately, installing aftermarket electrical components on newer vehicles, can cause major electrical problems if not done correctly. It is possible that during the installation, you may have created an electrical fault, causing some system sensors to either brake or store an electrical warning code in the ECU. This is quite probable if the battery was not disconnected during your stereo installation. Since we don’t offer repairs or maintenance on aftermarket parts or installs, I would recommend contacting a professional mechanic in your area to help you resolve this problem.

Supportive bar attached to brake pedal interrupts proper braking process
ANSWER : It’s possible to have someone alter the brake pedal or adapt a brake pedal from a different vehicle. You may call around to some customization shops to see if anyone is interested in taking on the project. But first, I would try reaching out to the selling dealer with your concern – especially since it is a new model. Good luck.

My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn’t start. Got a jump and
ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Grumbling sound while breaking at the stop light, brake pedal shakes
ANSWER : You are exactly right. It is your anti-lock braking system that is engaging when you hear that buzzing sound. A number of things could cause the anti-lock braking system to engage when it shouldn’t. Some of these things would include:

air in the brake system
one or more faulty wheel speed sensors
a faulty ABS control module
a faulty ABS pump

I would recommend having your braking system inspected by a technician who is proficient in anti-lock brake repairs. This inspection would cover all the parts listed to determine which one is causing the ABS malfunction.

When the inspection is completed, the mechanic would then relay the diagnostic information over to you to make a repair decision.

Noise when car starts and side noise brake
ANSWER : This is a common question among many Honda owners and is a valid question. This sound is usually due to the brake pads floating inside the brake calipers. I have seen numerous questions about this and had the same question myself when this design first came out. This design was intended to combat the oxidation or rust of calipers and caliper brackets which causes them to expand and create additional pressure on the pads themselves. When this happens, this can cause premature brake pad wear and breakdown of the brake pad lube (usually what is called Molykote) which then causes additional heat.

When this happens, depending on the amount of heat present, this can cause the caliper pins to freeze up causing the calipers to stick. This can cause excessive brake wear and damage. The intention of this design is purely preventative in nature and is generally not something that requires attention, however you may want to consult a professional from YourMechanic to have them come to you location to perform an inspection of your brakes to be sure this is actually the case and that they are not in need of further repair.

Car sounds like golf cart when revving and braking; also leaking fluid; sound fades as car warms up
ANSWER : Hello,
There are a number of things that could make an engine noisy when starting up. Depending on the specific type of sound you are referring to, this will determine how to properly diagnose. If there is a bit of a hissing sound, this may be a sign of a vacuum leak. If this is more of a shrieking sound, this may be a sign of a worn out or out of adjustment serpentine belt. If there is a bit of a howling or growling sound, this may be a sign of a worn out or low on fluid power steering pump. A rattling or pinging sound may be caused by an ignition problem. An engine can ping (or knock) due to an improper combustion process. A "spark knock" is the result of combustion occurring too early. Early combustion can occur from carbon buildup inside the combustion chamber, a lean air/fuel mixture, and advanced ignition timing (spark plug firing too soon). A clattering type sound may be a result of improper lubrication in the valve train which could be a more serious problem and should be addressed as soon as possible. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your vehicle to ensure everything is in proper working order.

My theft system is keeping my car from starting in my 1994 Cadillac Deville
ANSWER : Hello. If the theft light is coming on then it is causing the vehicle not to start. Most of the time the issue is caused by either the key failing or the key sensor located in the key lock cylinder. There is a small chip in the key that provides resistance value to the computer to tell it that the correct key is being used. If there was a spare key I would see if that works. If it does not then it is the sensor in the key lock cylinder. Most of the time the wires from the key lock cylinder break and cause this. It can also be caused by the theft module but that is not as common. If you need to have this problem repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the vehicle will not start] https://www.yourmechanic.com/services/car-is-not-starting-inspection

Driver has to pump brake pedal multiple times to brake
ANSWER : I’m not familiar with a pump assisting the system, but the master cylinder creates the hydraulic pressure needed to transfer power from your floor to the brake assemblies. A failing master cylinder can feel like a leak in the hydraulic system as it cannot create the proper pressure. Have a certified technician, like one from YourMechanic, physically inspect the brake system for any actual leaks as well.