How To Test And Adjust Your Car's Rear Drum Brakes

Aug 26, 2025 by Elias Adebayo 51 views

Hey guys! Let's dive into a crucial part of your vehicle's maintenance: testing and adjusting rear drum brakes. Drum brakes, while being a bit old-school compared to disc brakes, are still widely used, especially on the rear wheels of many cars, trucks, and SUVs. Keeping them in top shape is super important for your safety and the overall performance of your ride. So, let's get started and make sure those brakes are working perfectly!

Why Rear Drum Brakes Matter

First off, let's chat about why rear drum brakes are so important. Even though they're often playing second fiddle to the front disc brakes (which handle most of the stopping power), your rear drum brakes are still a vital part of your vehicle's braking system. They help to stabilize your car during braking, especially in emergency situations, and they're crucial for your parking brake to work correctly. Ignoring them can lead to some pretty hairy situations, like longer stopping distances or your car pulling to one side when you brake. Trust me, you don't want that!

Moreover, properly maintained rear drum brakes contribute significantly to the longevity of your entire braking system. When your rear brakes aren't doing their job, your front brakes have to work extra hard, which can cause them to wear out faster. So, by taking care of your rear drums, you're actually saving money in the long run by preventing premature wear on your front brakes. Plus, a well-maintained braking system ensures consistent and reliable performance, giving you peace of mind every time you hit the road. This is why regular inspection and adjustment of rear drum brakes are essential for overall vehicle safety and maintenance.

Now, think about this: when your rear drum brakes are out of whack, you might not even notice it right away. The symptoms can be subtle at first, like a slight decrease in braking performance or a soft brake pedal. But over time, these little issues can snowball into bigger problems, like damaged brake components or even brake failure. That's why it's so important to be proactive and check your rear drum brakes regularly. A little bit of maintenance can go a long way in preventing costly repairs and ensuring your safety on the road. So, let's get our hands dirty and make sure those brakes are in tip-top shape!

Recognizing the Signs: When to Check Your Brakes

Okay, so how do you know when it's time to check your rear drum brakes? There are a few telltale signs that your brakes might need some love. One of the most common signs is a soft or spongy brake pedal. This can indicate air in the brake lines or that your brake shoes aren't properly adjusted. Another sign is a decrease in braking performance. If you notice that it's taking longer to stop or that your car feels like it's pulling to one side when you brake, it's definitely time to take a look.

Another clue is any unusual noises coming from your brakes. Squealing, grinding, or scraping sounds are usually a sign that something's not right. Squealing can indicate worn brake shoes or a buildup of brake dust, while grinding or scraping noises often mean that your brake shoes are severely worn and you're hearing metal-on-metal contact. Ignoring these noises can lead to damage to the brake drums themselves, which can be a much more expensive repair. Also, pay attention to your parking brake. If it feels loose or doesn't hold the car securely, it could be a sign that your rear drum brakes need adjusting.

Don't forget about the mileage and time intervals recommended in your vehicle's owner's manual. Most manufacturers recommend inspecting your brakes every 15,000 to 30,000 miles, or at least once a year. Regular inspections can help you catch problems early before they turn into major issues. Plus, it's a good idea to check your brakes after any heavy braking situations, like driving in stop-and-go traffic or towing a trailer. So, keep an ear out for any unusual noises, pay attention to how your brake pedal feels, and stick to the recommended maintenance schedule. Your brakes will thank you for it!

Tools You'll Need

Before we get started, let's gather the tools you'll need for testing and adjusting your rear drum brakes. Having the right tools on hand will make the job much easier and safer. Here's a list of essentials:

Jack and Jack Stands: These are crucial for safely lifting and supporting your vehicle. Never work under a car supported only by a jack!
Wheel Chocks: Place these behind the wheels that will remain on the ground to prevent the car from rolling.
Lug Wrench: You'll need this to remove the lug nuts and take the wheels off.
Brake Spring Pliers: These specialty pliers are designed to safely remove and install the brake springs, which can be tricky to handle without the right tool.
Brake Adjustment Tool: This tool is used to adjust the star wheel adjuster inside the drum brake assembly. It's essential for getting the right brake shoe clearance.
Screwdrivers (various sizes): You'll likely need both flathead and Phillips head screwdrivers for various tasks.
Pliers: A pair of regular pliers can come in handy for gripping and manipulating small parts.
Brake Cleaner: This is used to clean the brake components and remove brake dust.
Gloves: Wearing gloves will protect your hands from dirt, grease, and brake dust.
Safety Glasses: Safety glasses are a must to protect your eyes from debris.
Shop Rags: You'll need these to wipe off dirt and grease.
Penetrating Oil: This can be helpful for loosening any stuck parts.
Torque Wrench: You'll need this to properly tighten the lug nuts when you reinstall the wheels.
Service Manual: Your vehicle's service manual will provide specific instructions and diagrams for your particular make and model.

Having these tools readily available will ensure that you can tackle the job efficiently and safely. Remember, safety should always be your top priority when working on your car's brakes. So, double-check that you have everything you need before you start, and don't hesitate to consult your service manual or a professional if you're unsure about any step.

Step-by-Step Guide: Testing Your Rear Drum Brakes

Alright, let's get into the nitty-gritty of testing your rear drum brakes. This is a crucial step before you start adjusting anything, as it helps you identify any issues that need attention. Here's a step-by-step guide to walk you through the process:

Safety First: Before you even think about touching your car, make sure it's parked on a level surface and engage the parking brake. Then, use wheel chocks behind the wheels that will remain on the ground to prevent any rolling.
Loosen the Lug Nuts: Use your lug wrench to loosen the lug nuts on the wheel you'll be working on. Don't remove them completely yet, just break them loose.
Lift the Vehicle: Now, grab your jack and position it under the designated jacking point for your vehicle (check your owner's manual for the exact location). Lift the car until the tire is off the ground.
Secure with Jack Stands: This is super important! Never work under a car supported only by a jack. Place jack stands under the frame or other designated support points, and then lower the car onto the stands.
Remove the Wheel: Now that the car is safely supported, you can remove the lug nuts completely and take the wheel off.
Inspect the Brake Drum: With the wheel off, you'll have a clear view of the brake drum. Look for any signs of damage, such as cracks, deep grooves, or excessive rust. If you see any significant damage, it might be time to replace the drum.
Check for Leaks: Inspect the area around the brake drum for any signs of brake fluid leaks. Leaks can indicate a problem with the wheel cylinder, which is a critical component of the drum brake system.
Measure Drum Diameter (Optional): If you have a brake drum micrometer, you can measure the inside diameter of the drum. Compare this measurement to the manufacturer's specifications. If the drum is beyond the maximum diameter, it needs to be replaced.
Check Brake Shoe Condition (If Visible): In some cases, you might be able to get a glimpse of the brake shoes through an inspection hole in the backing plate. Look for signs of wear, such as thin linings or uneven wear patterns. If the shoes are worn down to the rivets or metal backing, they need to be replaced.
Spin the Drum: Try spinning the brake drum by hand. It should rotate freely with only a slight drag. If it's difficult to turn or makes any grinding noises, it could indicate a problem with the brake shoes, wheel cylinder, or other components.
Reinstall the Wheel: Once you've completed your inspection, reinstall the wheel and tighten the lug nuts by hand. Then, lower the car back to the ground and use a torque wrench to tighten the lug nuts to the manufacturer's specified torque.
Repeat on the Other Side: Follow the same steps to test the rear drum brake on the other side of the vehicle.

By following these steps, you'll get a good sense of the condition of your rear drum brakes and identify any potential issues that need to be addressed. Now, let's move on to the adjustment process!

Step-by-Step Guide: Adjusting Your Rear Drum Brakes

Okay, now that we've tested the brakes, let's talk about adjusting your rear drum brakes. Proper adjustment is key to ensuring that your brakes work efficiently and effectively. Here's a step-by-step guide to help you through the process:

Safety First (Again!): Just like before, make sure your car is parked on a level surface, the parking brake is engaged, and the wheels are chocked. Loosen the lug nuts, lift the car, and secure it with jack stands before removing the wheel.
Locate the Adjustment Slot: On the backing plate of the brake assembly, you'll find an oval-shaped slot. This is where you'll access the star wheel adjuster. Sometimes, this slot is covered by a rubber plug, which you'll need to remove.
Insert the Brake Adjustment Tool: This is where your brake adjustment tool comes into play. Insert the tool into the adjustment slot, making sure it engages with the star wheel adjuster. You might need to try different angles to get it to catch.
Adjust the Star Wheel: The star wheel adjuster is used to expand or retract the brake shoes. Turning the star wheel in one direction will move the shoes outward, closer to the drum, while turning it in the opposite direction will retract them. The goal is to adjust the shoes so they have a slight drag against the drum.
Adjust One Side at a Time: Start by turning the star wheel a few clicks in one direction. Then, try spinning the brake drum by hand. If it spins freely, turn the star wheel a few more clicks. Keep adjusting until you feel a slight drag when you spin the drum. Be careful not to overtighten the brakes, as this can cause them to overheat and wear out quickly.
Check the Parking Brake: After adjusting one side, engage and disengage the parking brake several times. This helps to center the brake shoes and ensure they're properly adjusted. Then, try spinning the drum again to check for the slight drag.
Repeat on the Other Side: Follow the same steps to adjust the rear drum brake on the other side of the vehicle. It's important to adjust both sides equally to ensure balanced braking.
Reinstall the Wheel: Once you've adjusted both brakes, reinstall the wheels and tighten the lug nuts by hand. Then, lower the car back to the ground and use a torque wrench to tighten the lug nuts to the manufacturer's specified torque.
Test Drive: After adjusting your rear drum brakes, it's essential to take your car for a test drive. Start by driving slowly and gently applying the brakes to make sure they feel normal. Then, try some harder braking to ensure the brakes are working effectively and the car stops straight.
Fine-Tune if Necessary: If you notice any issues during your test drive, such as the brakes feeling too tight or too loose, you can repeat the adjustment process to fine-tune the brakes. It might take a few tries to get them just right.

Adjusting rear drum brakes can seem a bit tricky at first, but with a little patience and the right tools, you can definitely do it yourself. Just remember to take your time, follow the steps carefully, and don't be afraid to consult your service manual or a professional if you're unsure about anything.

Common Mistakes to Avoid

Okay, let's talk about some common mistakes to avoid when testing and adjusting your rear drum brakes. Knowing these pitfalls can save you time, frustration, and even prevent damage to your brakes. So, listen up!

Skipping the Safety Steps: This is the biggest mistake you can make. Never, ever work under a car that's only supported by a jack. Always use jack stands to secure the vehicle before you start working. And don't forget to use wheel chocks to prevent the car from rolling. Safety first, always!
Overtightening the Brakes: It's tempting to adjust the brakes until they feel super tight, but overtightening can lead to serious problems. If the brake shoes are too close to the drum, they can overheat, causing the brake linings to wear out quickly and potentially damaging the drums. The goal is to adjust the brakes until there's a slight drag, not a complete lockup.
Forgetting to Adjust Both Sides: It's crucial to adjust both rear drum brakes equally. If one side is tighter than the other, it can cause the car to pull to one side when you brake, which is not only annoying but also dangerous.
Using the Wrong Tools: Using the wrong tools can make the job much harder and even damage your brakes. For example, trying to remove brake springs without brake spring pliers can be a recipe for disaster. Invest in the right tools for the job, and you'll save yourself a lot of headaches.
Ignoring Rust and Corrosion: Rust and corrosion can prevent the brake components from moving freely, which can affect braking performance. Before adjusting your brakes, take the time to clean off any rust or corrosion with a wire brush or brake cleaner.
Not Checking for Leaks: Brake fluid leaks are a serious issue that needs to be addressed immediately. If you see any signs of brake fluid leaking around the wheel cylinder or brake lines, don't just adjust the brakes and hope for the best. Fix the leak first!
Reassembling Incorrectly: Drum brake assemblies can be a bit complex, with lots of springs and small parts. It's easy to get things mixed up if you're not careful. Take photos as you disassemble the brakes so you have a reference for reassembly. And if you're not sure about something, consult your service manual or a professional.

By avoiding these common mistakes, you'll be well on your way to successfully testing and adjusting your rear drum brakes. Remember, patience and attention to detail are key!

When to Call a Professional

Okay, so we've covered a lot about testing and adjusting rear drum brakes. But let's be real, sometimes it's best to call in the pros. Knowing when to throw in the towel and seek professional help can save you a lot of stress, money, and potential safety issues. So, when should you consider calling a mechanic?

If You're Not Comfortable: This is the most important reason. If you're feeling overwhelmed or unsure about any step of the process, don't hesitate to call a professional. Brakes are a critical safety component, and it's better to be safe than sorry.
If You Encounter Major Damage: If you find significant damage to your brake drums, such as deep cracks or excessive wear, it's time to call a mechanic. These types of repairs often require specialized tools and expertise.
If You Suspect a Wheel Cylinder Issue: If you notice brake fluid leaks or suspect a problem with the wheel cylinder, it's best to have a professional take a look. Wheel cylinder repairs can be complex and require bleeding the brake system, which is a crucial step for safety.
If You Can't Get the Brakes Adjusted Properly: If you've tried adjusting your rear drum brakes and they still don't feel right, it could indicate a more serious problem. A professional mechanic can diagnose the issue and make the necessary repairs.
If You Hear Grinding or Scraping Noises: These noises often indicate severe brake wear and can mean that your brake shoes or drums are damaged. Ignoring these noises can lead to further damage and even brake failure.
If Your Car Pulls to One Side When Braking: This is a sign that your brakes are not working evenly, which can be dangerous. A professional mechanic can diagnose the cause of the pulling and make the necessary adjustments or repairs.
If You're Replacing Brake Shoes or Hardware: While replacing brake shoes and hardware is a DIY-able task, it can be a bit involved. If you're not comfortable with the process, or if you encounter any difficulties, it's best to call a professional.

Remember, your safety is paramount. If you're ever in doubt about your ability to safely test or adjust your rear drum brakes, don't hesitate to seek professional help. A qualified mechanic can ensure that your brakes are working properly and that you're safe on the road.

Final Thoughts

Alright guys, we've covered a lot about testing and adjusting your car's rear drum brakes. It might seem like a daunting task at first, but with the right knowledge and tools, it's something you can definitely tackle yourself. Remember, regular maintenance is key to keeping your brakes in top shape and ensuring your safety on the road. By recognizing the signs of brake problems, following the step-by-step guides, and avoiding common mistakes, you can keep your rear drum brakes working smoothly for years to come.

However, don't forget that safety is always the top priority. If you're ever unsure about any aspect of brake maintenance, or if you encounter a problem that's beyond your comfort level, don't hesitate to call a professional mechanic. They have the expertise and equipment to handle more complex brake repairs and ensure that your car is safe to drive. So, stay safe out there, and happy braking!