4 Symptoms of Bad Brake Drums (& Replacement Cost)

Symptoms of Bad Brake Drums

The health of your car’s braking system is vital for your on-road safety. If your vehicle comes equipped with brake drums, you want to be sure that you are paying close attention to any signs that there is a problem. When the symptoms of bad brake drums occur, this system demands your immediate attention.

We review four issues you should be on the lookout for. Our guide also shows you what a brake drum does and where to find it. In the end, we discuss how much you can expect to pay to replace the brake drums. 

Bad Brake Drums Symptoms

1. Trouble Stopping

car brake distance

When you step on the brake pedal, you expect your vehicle to stop in a timely fashion. As the brake drums start to wear, this stopping time will gradually increase. If the car isn’t stopping as it once did, it could be an issue with either the drums or the brake shoes.

However, your vehicle might come equipped with brake drums on the back wheels and discs on the front. In this case, it can be difficult to tell which set is going bad because both cause stopping issues when they are worn. 

2. Brake Noise

noise from car

When the brakes are operating normally, there should be no unusual sounds when you step on the pedal. However, the brakes become louder as they wear. 

Bad brake drums can no longer absorb the heat that is generated during braking. As the heat builds up, it causes additional stress on the brakes, leading to scraping noises when the shoes touch the drums. 

3. Vibrating Brake Pedal

brake pedal push

As the brake drums get worse, you will notice performance issues with the pedal as well. When you step down on the brake pedal to stop the vehicle, you might notice some vibrations. At first, you might not give it much thought, especially if no other symptoms have started yet.

However, this early warning sign is attempting to get your attention. If you replace the brake drums now before the other problems occur, you can save yourself a lot of trouble and ensure maximum stopping power. 

RELATED: 5 Causes Why Your Brake Pedal Goes to Floor When Engine Running or Starts

4. Loose Parking Brake

pull parking brake

The majority of vehicles use the parking brake with the back wheels. This is also where most brake drums are found. The parking brake counts on reliable brake drums to keep the vehicle secure when applied. 

If the drums are worn, they might not have the holding power needed to keep the vehicle in place. At first, you might notice a loose-feeling parking brake when you go to apply it. It can also feel like it slips slightly after being applied. 

Brake Drum Location

The drum brakes can be found on rear wheels because that is where the parking brake is usually located. Brake drums are circular and made of metal. It’s also where the brake shoes are housed.

The drum brakes turn with the wheel and are connected to the hubs. However, they are just one part of the complete drum braking system. A typical system contains brake shoes to press into the drums and a backing plate to hold everything together. The system also has the brake cylinder with the pistons attached and return springs that alter the position when the brakes aren’t applied. 

RELATED: 4 Symptoms of Bad or Worn Brake Shoes

The Function of a Brake Drum

brake drums

When you push the brake pedal, the hydraulic brake fluid causes the pistons to push into the brake shoes. When this happens, the shoes push into the drums, causing the wheels to slow down and stop rotating. 

When you release the brake pedal, the return springs ensure that the shoes move back into their original position. This action allows the wheel to have free movement once again, without the shoes pressing into it. 

As the brake shoe surface wears down, the position needs to be adjusted. Otherwise, the shoes will have too far of a distance to travel when making contact with the brake drum. 

Brake Drum Replacement Cost

The cost to replace brake drums is typically between $200 and $250. The parts alone are typically between $150 and $200, while the rest is spent on labor. If you can replace the drums yourself, you can save a small amount of money. Additionally, aftermarket drums cost less than many OEM versions unless you are upgrading to high-performance drums. 

Thankfully, drum brakes rarely require replacement and can often last 200,000 miles when used properly. You purchase brake drums individually or you can buy them as part of a kit, which includes the two-wheel set and the hardware needed for installation. 

If you are replacing the drum brakes on one side, it’s often advised to do the same on the other side. The problems that led to wearing on one side are probably causing wear to the other. It’s best to keep the performance of both drum brakes the same.

If you replace the brake drums it is also very smart to replace the brake shoes and the cylinders at the same time.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. He has also been a motorsport (drifting) driver for over 5 years.