To adjust drum brakes, first, remove the wheel and locate the adjuster hole on the backing plate. Then, use a brake spoon to turn the adjuster wheel until the brake shoes lightly touch the drum.
Properly adjusting drum brakes is essential for vehicle safety and performance. Whether you’re a seasoned mechanic or a DIY enthusiast, knowing how to adjust drum brakes can save you time and money. By following a few simple steps, you can ensure that your drum brakes operate smoothly and effectively.
In this guide, we’ll walk you through the process of adjusting drum brakes, providing you with the knowledge and confidence to tackle this essential maintenance task.
Drum Brakes
Before diving into the adjustment process, it’s important to understand how drum brakes work. Drum brakes consist of several key components:
- Brake Drum: A cylindrical drum attached to the wheel that rotates with it.
- Brake Shoes: Curved friction material that presses against the inside of the brake drum to create braking force.
- Wheel Cylinder: A hydraulic component that pushes the brake shoes outward when the brake pedal is pressed.
- Return Springs: Springs that pull the brake shoes back to their original position when the brake pedal is released.
- Adjuster Mechanism: A device that automatically adjusts the brake shoes’ position as they wear down over time. However, manual adjustment is often necessary to ensure optimal performance.
Drum brakes are typically self-adjusting, but over time, wear and tear can cause the self-adjuster to become less effective, requiring manual adjustment.
How to Adjust Drum Brakes
Before starting, gather the following tools and materials:
- Jack and Jack Stands: To safely lift and support the vehicle.
- Lug Wrench: To remove the wheel.
- Brake Spoon or Flathead Screwdriver: To adjust the brake shoes through the adjustment slot.
- Pliers: For manipulating springs and other components.
- Brake Cleaner: To clean the drum and components.
- Shop Rags: For wiping down parts.
- Safety Equipment: Gloves, safety glasses, and a dust mask.
Step-by-Step Guide to Adjusting Drum Brakes
Follow the steps below to do the job successfully –
1. Prepare the Vehicle
- Park on a Level Surface: Ensure your vehicle is on a flat, stable surface. Engage the parking brake and place wheel chocks behind the front wheels if you’re adjusting the rear brakes.
- Loosen the Lug Nuts: Using a lug wrench, slightly loosen the lug nuts on the wheels where you’ll be adjusting the brakes. Do this before jacking up the vehicle.
- Lift the Vehicle: Use a jack to lift the vehicle at the appropriate jacking points. Secure the vehicle with jack stands to ensure stability.
- Remove the Wheel: Fully remove the lug nuts and take off the wheel to access the drum brake assembly.
2. Access the Brake Drum
- Remove the Brake Drum: Some drums may slide off easily, while others might be held in place by rust or retaining screws. If the drum is stuck, gently tap it with a rubber mallet around the edge to loosen it.
- Inspect the Components: Before adjusting, inspect the brake shoes, drum, and other components for wear. Replace any worn or damaged parts as necessary. If the drum is excessively worn, it may need to be machined or replaced.
3. Clean the Brake Assembly
- Use Brake Cleaner: Spray brake cleaner on the drum, shoes, and other components to remove dust and debris. Brake dust can be hazardous, so wear a mask and avoid inhaling the particles.
- Wipe Down Components: Use shop rags to wipe down the cleaned components. Ensure that the area is dry and free of any contaminants.
4. Adjust the Brake Shoes
- Locate the Adjuster Mechanism: The adjuster is usually a star wheel located at the bottom of the brake assembly. It’s accessible through an adjustment slot on the back of the brake drum or through the face of the drum, depending on your vehicle’s design.
- Insert the Brake Spoon or Screwdriver: Insert the tool into the adjustment slot and engage the teeth of the star wheel.
- Turn the Adjuster: Rotate the star wheel to expand the brake shoes outward. If the wheel spins freely, the brakes are too loose, and the adjuster should be turned to move the shoes closer to the drum. Be cautious not to over-tighten; the drum should fit snugly over the shoes but still rotate without excessive resistance.
- Check the Fit: Once adjusted, slide the drum back onto the brake assembly and rotate it by hand. It should have a slight drag, indicating the shoes are making light contact with the drum. If there’s too much resistance, back off the adjuster slightly.
5. Reassemble and Test
- Reattach the Drum and Wheel: Once satisfied with the adjustment, replace the brake drum. Reinstall the wheel and hand-tighten the lug nuts.
- Lower the Vehicle: Carefully remove the jack stands and lower the vehicle back to the ground.
- Tighten the Lug Nuts: Once the vehicle is on the ground, fully tighten the lug nuts in a star pattern to ensure even torque.
6. Test the Brakes
- Pump the Brake Pedal: Before driving, pump the brake pedal a few times to ensure the shoes are properly seated and that the pedal feels firm.
- Test Drive: Take the vehicle for a slow test drive in a safe area. Listen for any unusual noises and check for proper braking performance. The vehicle should stop smoothly and evenly.
Tips and Warnings
- Check Both Sides: Always adjust the brakes on both sides of the axle to ensure even braking.
- Monitor Brake Performance: After adjusting, keep an eye on brake performance over the next few days. If you notice uneven braking or pulling to one side, recheck your work.
- Stay Safe: Always work in a well-ventilated area and use proper safety equipment. Brake dust contains harmful materials, including asbestos in older vehicles, so avoid inhaling it.
When to Adjust Drum Brakes
While drum brakes are designed to be self-adjusting, certain situations may require manual adjustment:
- Uneven Braking: If your vehicle pulls to one side when braking, it could indicate uneven adjustment.
- Spongy Brake Pedal: A soft or spongy brake pedal may indicate that the brake shoes are too far from the drum.
- Increased Stopping Distance: If your vehicle takes longer to stop, it may be due to improperly adjusted drum brakes.
- Brake Noise: Squealing or grinding noises can indicate worn or improperly adjusted brake shoes.
Frequently Asked Questions
Here are some FAQs about the drum brake –
How Tight Should My Drum Brakes Be?
Drum brakes should be adjusted so that they are snug, but not too tight. You should be able to spin the wheel freely without any drag, but also without any excessive play. The brake shoes should make contact with the drum evenly and not be over-tightened.
Always refer to your vehicle’s owner’s manual for specific instructions.
How Do I Know If My Drum Brakes Need To Be Adjusted?
To determine if your drum brakes need adjustment, listen for any squeaking or grinding sounds when you apply the brakes. If your vehicle pulls to one side while braking, this may also indicate the need for adjustment. Additionally, if the brake pedal feels soft or requires more pressure to engage, it could be a sign of brake adjustment issues.
Can You Adjust Rear Drum Brakes By Backing Up?
Yes, you can adjust rear drum brakes by backing up. This helps to self-adjust the brakes as the shoes move against the drums.
How To Manually Adjust Drum Brakes?
To manually adjust drum brakes, locate the adjuster wheel and turn it to tighten or loosen the brakes. Test the brakes afterward for proper adjustment.
How Do I Know If My Drum Brakes Need Adjusting?
If your brake pedal feels soft or the car takes longer to stop, it’s time to adjust your drum brakes.
Conclusion
Adjusting drum brakes is a crucial maintenance task that can significantly impact your vehicle’s safety and performance. While modern vehicles often feature disc brakes, drum brakes remain common in many cars, particularly in the rear. By following the steps outlined in this guide, you can ensure your drum brakes are properly adjusted, providing reliable braking performance. Regular maintenance and adjustments will not only extend the life of your brake components but also contribute to a safer driving experience.
Remember, if you’re not comfortable performing brake adjustments yourself, it’s always a good idea to consult a professional mechanic. Proper brake maintenance is essential for your safety and the safety of others on the road.