Your brakes are one of the most essential parts of your semi-truck, making it safe for drivers to operate on the road around other motorists. Squealing brakes can be obnoxious and distracting for drivers, especially long haulers. Apart from the annoyance that noisy brakes cause, it can also indicate that something is wrong with your semi-truck brake system. Determining the noise source is crucial to your driver's safety.

There are multiple reasons semi-truck brakes can squeal, from worn brake pads to moisture and rust. Learn about some of the common causes of squealing brakes and what you can do to fix them below.

What Causes Semitruck Brakes to Squeal?

Squeaking brakes can be annoying at best but can also indicate a serious problem. Some common causes of semi-truck brake noise include:

• Worn semi-truck brake pads: Worn brake pads are one of the most common causes of squealing brakes since these parts are usually designed with a metal indicator that creates a high-pitched noise when the pads reach minimum thickness. This noise is a clear sign it's time for you or a mechanic to replace them. The sound should disappear after a few brake applications. If it persists after you change the brake pads, investigate the issue immediately since it can indicate damaged rotors, brake drum issues, or similar problems.
• Damaged rotors: Semi-truck rotors lose smoothness over time, causing brake squealing. Rust on your rotors can also cause unpleasant noises. If the rust has built up, a mechanic can file it off to eliminate the source of the noise and keep your rotors in working condition.
• Debris between the pads and rotors: When dirt, mud, and debris get between brake pads and rotors, it can cause a squealing noise when you press the brakes. Semi-trucks that have been idle or those that drive on dusty terrain are more likely to develop this problem. Sometimes, this problem can go away on its own with a few brake applications. You may need to clean the space between the pads and rotors to eliminate the source of the squealing.
• Moisture: If your brakes make sounds first thing in the morning, it could be because it was exposed to rain, excessive humidity or snowfall. Moisture that settles on brakes can create a thin layer of rust, which may be the source of the squealing. You can typically fix minimal build-up with normal driving since the pressure between the brake pads and rotors will help eliminate this buildup. 
• Brake drum issues: Brake drums can also be the source of brakes squealing if they lack lubrication between the drum and shoes. You can typically tell if your brake drum is the cause of the squealing by looking at the exposed metal, where you should see signs of scraping.

If your brakes are brand new, any squeaking should subside after you've driven with them a few times.

How Can You Fix Squealing Semitruck Brakes?

Once you've determined the source of your squealing brakes, you can take steps to quickly repair and end the noise. Some semi-truck brake repairs you may need to perform include the following:

• Replacing the brake pads: Since worn brake pads are one of the most common sources of squealing, replacing these parts is often an easy way to end the noise. Your mechanic can inspect the brake pads to determine if they're the source of the squealing and replace or repair them if necessary. You may also need a semi-truck brake adjustment to reduce or eliminate the squealing.
• Replacing the rotors: If you've been driving too long on worn brake pads, it can damage the rotors. If your rotors cause noise, have a mechanic replace them. If your rotors are still thick enough, your mechanic may be able to machine them to improve their finish rather than a full replacement.
• Cleaning between pads and rotors: If dirt or debris between the pads and rotors is causing squealing brakes, you or a mechanic can fix this problem by cleaning between them.
• Lubricating your brake drum: If your brake drum is the source of the squealing, a mechanic can help you remove the drum and shoes. They'll lubricate the backing plate and replace the drum and shoes, eliminating squealing. 
• Keeping your truck away from moisture: Keeping your semi-truck away from the elements can be challenging. Try to keep your semi-truck out of direct rain or snowfall to reduce the risk of a thin layer of rust developing on the brakes. If you can't keep your semi-truck from moisture, you can prevent rusting from getting worse by driving the truck regularly. 

While you may be able to repair some of these problems yourself, you always want to consult a professional regarding your brakes. Your brakes are an essential part of your semi-truck and must be kept in the best condition for the safety of your drivers and other motorists. A professional can determine the source of the problem and ensure the repairs are performed correctly so you can get back on the road safely. 

Brake Noise Prevention

The best way to prevent problems with your brakes and squealing is to schedule regular truck maintenance. Regular maintenance can help you catch problems before they become more significant, such as squealing brakes that can distract drivers or sounds that indicate larger concerns. You can also try lubricating the brake pads or adding a set of brake pad shims.

Check your brakes regularly for any signs of trouble, such as:

• Thinning brake pads.
• Rusting components.
• Dirt or debris between the rotor pads.
• Limited lubrication.

Some brakes also have a built-in wear indicator you can monitor. Noticing these problems can reduce the chance of squealing and damage that can pose a safety risk when a driver is on the road. Consider creating a full maintenance plan for your vehicle to inspect each part regularly, and train drivers to spot concerns quickly.

Trust Thompson Truck Store to Service Your Semi-Truck Brakes

If your brakes are squealing and putting your drivers at risk, Thompson Truck Source can help. We offer full-service maintenance and repairs to help you keep your semi-trucks in the best condition for the road. We can help you determine the noise source and manage repairs as quickly as possible, helping you get back on the road and reducing your downtime. 

We also offer a wide range of parts to help you replace any components in your semi-truck that may be causing the problem. Our selection of semi-truck parts is high-quality and reliable, ensuring you get the best performance possible. Contact us to learn more about how we can help or to get started on your service!