Your car’s brakes are its most crucial safety system, responsible for bringing your vehicle to a safe stop. While disc brakes are becoming increasingly common, drum brakes still play a vital role in many vehicles, particularly older models and those in the rear axle. Understanding how drum brakes work and how to service them is essential for any car owner who wants to ensure their safety and the longevity of their vehicle. One common maintenance task is removing a drum brake, which may be necessary for replacing worn brake shoes, adjusting the brake mechanism, or inspecting the internal components for damage. This comprehensive guide will walk you through the process of removing a drum brake, providing step-by-step instructions and valuable insights to make the task easier and safer.
Table of Contents
- Understanding Drum Brakes
- Preparing for Drum Brake Removal
- Removing the Drum Brake
- Inspecting and Replacing Brake Components
- Reinstalling the Drum Brake
- Bleeding the Brakes
- Recap and Key Points
- Frequently Asked Questions
- How often should I replace my drum brakes?
- Can I resurface my drum brakes?
- What causes a sticking drum brake?
- How do I adjust my drum brakes?
- What are the signs of worn drum brakes?
Understanding Drum Brakes
Drum brakes are a type of braking system that utilizes friction between a set of brake shoes and a rotating brake drum. When the brake pedal is pressed, hydraulic pressure forces the brake shoes outward, pressing against the inside surface of the drum. This friction slows down the rotation of the drum, ultimately bringing the vehicle to a stop. Drum brakes are known for their durability and ability to handle high braking forces, but they can be more prone to wear and tear than disc brakes.
Components of a Drum Brake System
Here’s a breakdown of the key components found in a typical drum brake system:
* **Brake Drum:** The cylindrical metal component that rotates with the wheel.
* **Brake Shoes:** Friction material-lined pads that press against the inside of the drum to create braking force.
* **Wheel Cylinder:** A hydraulic cylinder that receives brake fluid pressure and pushes the brake shoes outward.
* **Brake Adjuster:** A mechanism that automatically adjusts the clearance between the brake shoes and the drum, ensuring optimal braking performance.
* **Parking Brake Lever:** A separate lever that activates a cable connected to the rear brakes, engaging the parking brake.
Preparing for Drum Brake Removal
Before you begin removing a drum brake, it’s crucial to take the necessary safety precautions and gather the required tools.
Safety First
* **Park on a level surface:** Ensure your vehicle is parked on a flat, stable surface with the parking brake engaged.
* **Chock the wheels:** Place wheel chocks behind the front wheels to prevent the vehicle from rolling.
* **Disconnect the battery:** Disconnect the negative battery terminal to avoid any electrical shorts.
Tools You’ll Need
* **Socket wrench set:** For removing lug nuts and brake hardware.
* **C-clamp or brake drum puller:** To remove the drum from the hub.
* **Hammer and punch:** For tapping out stubborn brake components.
* **Flat-head screwdriver:** For prying apart brake components.
* **Brake cleaner:** To clean the brake components.
* **Grease:** To lubricate brake components.
* **Work gloves:** To protect your hands.
* **Safety glasses:** To protect your eyes.
Removing the Drum Brake
Now that you’re prepared, let’s proceed with the step-by-step removal process: (See Also: How to Get Brake Dust Off Aluminum Wheels? Easy Cleaning Tips)
1. **Remove the wheel:** Loosen the lug nuts on the wheel using a socket wrench, then remove them completely. Carefully lift the wheel off the hub.
2. **Inspect the brake hardware:** Examine the brake hardware, including the brake lines, wheel cylinder, and brake adjuster, for any signs of damage or wear.
3. **Remove the brake drum:** Use a C-clamp or brake drum puller to carefully remove the drum from the hub. Apply even pressure to avoid damaging the drum or hub.
4. **Disconnect the brake lines:** If necessary, disconnect the brake lines from the wheel cylinder. Use a wrench to loosen the fitting and carefully guide the line away from the cylinder.
5. **Remove the wheel cylinder:** The wheel cylinder may be secured with a retaining clip or bolts. Remove these fasteners and carefully pull the wheel cylinder out of the backing plate.
Inspecting and Replacing Brake Components
With the drum brake removed, you can now thoroughly inspect all the components for wear and tear.
Inspecting Brake Shoes
* **Thickness:** Check the thickness of the brake shoes. If they are worn down to a specified minimum thickness (refer to your vehicle’s repair manual), they need to be replaced.
* **Condition:** Look for any cracks, tears, or glazing on the brake shoes. Damaged shoes should be replaced.
Inspecting the Brake Drum
* **Scoring:** Examine the drum for any scoring or grooves on the braking surface. If the damage is excessive, the drum may need to be resurfaced or replaced.
* **Warpage:** Check for any warping or unevenness in the drum. Warped drums can cause pulsating brake pedal feel.
Inspecting Other Components
* **Wheel Cylinder:** Inspect the wheel cylinder for leaks or damage. If it is leaking, it needs to be replaced.
* **Brake Adjuster:** Make sure the brake adjuster is functioning properly. If it is stuck or damaged, it needs to be replaced.
Reinstalling the Drum Brake
Once you have inspected and replaced any necessary components, you can begin reinstalling the drum brake.
1. **Clean the components:** Thoroughly clean all the brake components with brake cleaner.
2. **Lubricate the components:** Apply a thin layer of grease to the contact points between the brake shoes and the backing plate, as well as to the wheel cylinder piston seals.
3. **Install the wheel cylinder:** Carefully insert the wheel cylinder into the backing plate and secure it with the retaining clip or bolts.
4. **Install the brake shoes:** Position the brake shoes in the backing plate, ensuring they are properly seated.
5. **Install the brake drum:** Slide the brake drum onto the hub, ensuring it is properly aligned.
6. **Connect the brake lines:** Reconnect the brake lines to the wheel cylinder, tightening the fittings securely.
7. **Install the wheel:** Place the wheel back onto the hub and tighten the lug nuts in a star pattern. (See Also: What Causes the Brake Light to Come On? – Troubleshooting Guide)
Bleeding the Brakes
After reinstalling the drum brake, it’s essential to bleed the brakes to remove any air bubbles from the hydraulic system. Air bubbles can cause a spongy brake pedal feel and reduce braking performance.
1. **Locate the bleeder screw:** The bleeder screw is typically located on the brake caliper or wheel cylinder.
2. **Connect a brake bleeder hose:** Attach a brake bleeder hose to the bleeder screw.
3. **Place the hose in a container:** Position the other end of the hose in a container filled with brake fluid.
4. **Open the bleeder screw:** Have an assistant depress the brake pedal several times while you slowly open the bleeder screw.
5. **Close the bleeder screw:** Once you see a steady stream of brake fluid flowing from the hose, close the bleeder screw.
6. **Repeat the process:** Repeat steps 4-5 for each wheel cylinder or brake caliper in the system.
Recap and Key Points
Removing and reinstalling a drum brake is a relatively straightforward process that can be accomplished with the right tools and knowledge. By following the steps outlined in this guide, you can safely and effectively service your drum brakes, ensuring optimal braking performance and safety.
Here are the key takeaways from this guide:
* **Safety First:** Always prioritize safety when working on your vehicle. Park on a level surface, chock the wheels, and disconnect the battery.
* **Inspect Components:** Thoroughly inspect all brake components for wear and tear before reinstalling.
* **Bleeding is Essential:** Bleeding the brakes after replacing components is crucial for proper hydraulic function.
* **Proper Lubrication:** Lubricate the contact points between brake components to ensure smooth operation and prevent premature wear.
Frequently Asked Questions
How often should I replace my drum brakes?
The lifespan of drum brakes varies depending on driving habits, road conditions, and vehicle usage. As a general guideline, it’s recommended to inspect your drum brakes every 12,000 to 15,000 miles. If you notice any signs of wear or damage, such as thin brake shoes or scored drums, it’s time for replacement. (See Also: How Much Is A New Brake Rotor? Prices Revealed)
Can I resurface my drum brakes?
Yes, drum brakes can be resurfaced to remove minor scoring or grooves. However, if the drum is warped or severely damaged, it’s best to replace it. A professional mechanic can determine if resurfacing is possible and recommend the best course of action.
What causes a sticking drum brake?
A sticking drum brake can be caused by several factors, including: worn brake shoes, contaminated brake fluid, a seized wheel cylinder, or debris stuck between the brake shoes and drum. It’s important to address this issue promptly, as a sticking brake can lead to overheating and brake failure.
How do I adjust my drum brakes?
Drum brakes have an automatic adjuster that typically maintains proper clearance between the brake shoes and drum. However, if the adjuster is malfunctioning or the brakes need to be adjusted manually, refer to your vehicle’s repair manual for specific instructions. It often involves using a tool to turn the adjuster star wheel.
What are the signs of worn drum brakes?
Common signs of worn drum brakes include: a grinding or squealing noise when braking, a pulsating brake pedal, reduced braking effectiveness, and visible wear on the brake shoes.
