do you have to bleed drum brakes

Do You Have to Bleed Drum Brakes?

When it comes to vehicle maintenance, ensuring that your braking system is in optimal condition is imperative for safety. Drum brakes, while often considered older technology compared to disc brakes, are still found on many vehicles, especially in the rear brakes of some cars and on heavier vehicles like trucks and buses. One important aspect of maintaining drum brakes is the process of bleeding them, but many car owners wonder if this is a necessity. This article will delve into the reasons behind bleeding drum brakes, the process involved, and when it’s essential to perform this task.

Understanding the Importance of Bleeding Brakes

Bleeding brakes refers to removing air trapped in the brake lines. Air in the brake system can lead to a spongy brake pedal feel, decreased braking efficiency, and potentially dangerous situations where the brakes do not engage properly. Drum brakes, like any braking system, rely on hydraulic pressure to operate effectively. If air gets into the hydraulic lines, it can compress more easily than the brake fluid, leading to reduced braking force.

Notably, drum brakes tend to trap more air than disc brakes, especially during repairs or maintenance procedures that involve removing the brake lines or wheel cylinders. Therefore, if you notice that your vehicle’s braking performance has degraded, or if you’ve recently performed brake maintenance, bleeding the drum brakes becomes necessary.

Identifying When to Bleed Drum Brakes

There are specific situations where bleeding drum brakes is crucial

1. After Replacing Brake Components If you've replaced the wheel cylinders, brake shoes, or any part of the hydraulic system, it's important to bleed the system to ensure any air introduced during the repair is eliminated.

2. Brake Fluid Change Brake fluid should be changed periodically as it absorbs moisture over time, which can compromise braking performance. During a fluid change, bleeding the system ensures that new fluid is uniformly distributed and that any trapped air is removed.

3. Spongy Brake Pedal If your brake pedal feels spongy, this is a sign that air is present in the brake lines. Bleeding the brakes can restore a firm pedal feel.

4. Brake Warning Light Many vehicles will have a warning light that indicates a problem with the braking system, which may necessitate investigation and possibly bleeding of the brakes.

Bleeding drum brakes can be done at home with the right tools. Here's a step-by-step guide to the process

1. Gather Your Materials You will need brake fluid, a clear plastic tube, and a wrench to loosen the bleeder screws on the wheel cylinders.

2. Prepare the Vehicle Ensure that the vehicle is on a level surface and secure it with wheel chocks. Lift the vehicle and remove the wheels covering the drum brakes.

3. Locate the Bleeder Screw Each wheel cylinder in the drum brake assembly has a bleeder screw. It is usually located at the top of the cylinder.

4. Attach the Tube Place one end of the clear tube over the bleeder screw and the other end into a container to catch the leftover fluid.

5. Open the Bleeder Screw Using the wrench, slowly open the bleeder screw while someone else gently presses the brake pedal. You will observe brake fluid and possibly air bubbles coming through the tube.

6. Close the Screw Once fluid flows out without bubbles, close the bleeder screw and have the assistant release the brake pedal.

7. Repeat Repeat this process on each wheel, typically starting from the farthest wheel from the master cylinder.

8. Check Fluid Level Ensure the brake fluid reservoir is topped off during the process to prevent introducing more air into the system.

Conclusion

In conclusion, bleeding drum brakes is indeed an important procedure that every vehicle owner should consider, particularly after replacing parts, bleeding air from the system, or noticing changes in brake response. By understanding the significance of this maintenance task, you contribute not only to the longevity of your braking system but also to your safety on the road. Always consult your vehicle’s manual for specific instructions and consider seeking professional assistance if you are unsure about any aspect of the process. Safe driving!