How To Remove Brake Drums
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Drum brakes represent a prevalent braking alternative utilized in many vehicles nowadays. Although disc brakes have become the norm for employment on many vehicles' front and rear axles, drum brakes remain commonplace.
Brake drums are typically situated on the rear axle of a vehicle and function as the vehicle's parking brake.
Although disc and drum brakes are widely available in various vehicle platforms and represent secure and dependable braking options, they differ substantially in design and operation.
Specifically, drum brakes incorporate frictional brake shoes within a drum, unlike brake pads that operate atop a disc brake rotor.
Let’s look at all you need to know about removing brake drums.
Table of Contents
How Does Brake Drum Work? (Brake Shoes)
Some vehicles are fitted with a brake system known as a disc-drum setup, which pertains to the style of brakes located at the front and rear of the vehicle.
Rear drum brakes have been the automotive industry's norm for years and are less efficient than their rear disc brake counterparts, despite being less costly to produce. Hence, they are typically featured only on the rear of a vehicle.
Brake shoes are bought in four sets, with two on each side, which may include two distinct brake shoes per side.
The primary shoe, which is installed toward the front of the vehicle, has slightly less friction material than the secondary shoe, which is located toward the rear and has a little more material.
If the brake shoes have the same friction material, it does not matter how installed.
The rear brake shoes perform the emergency brake job on drum brakes. The emergency brake system's mechanical activation utilizes the same principle of pushing the shoes outward against the drum to assist in holding the car in place.
In contrast, vehicles with rear disc brakes use a smaller drum brake in the center of the rotor.
What Makes Brake Drums Go Bad?
Under regular driving conditions, friction between the shoe and drum will remove the brake material from the shoe.
When the brake material depreciates, the brake pedal will travel further down than it should, which gives the feeling the brakes are also not working. The rear brake shoes must be replaced if a car's parking brake doesn't hold.
Brake fluid leaks are also an issue as the wheel cylinder seals often leak, coating the brake shoes with brake fluid.
If the rear axle seal leaks, it coats the brake shoes with gear oil, grabbing and locking them up. It seems surprising that oil and brake fluid would lock the brakes up because you could allow the brakes to slip and slide.
Rear drum brakes tend to grab and lock up even without introducing brake fluid or gear oil. This is due to over-worn shoes contacting too much surface area inside the drum.
Locking up can be due to the sprung brake shoe, which allows the very top and bottom of the shoe to contact the drum. The center of the shoe must be the only part that contacts the drum.
Brake Drum vs. Disk Brakes
The rear axle of a vehicle is typically outfitted with drum brakes, whereas the front and rear axles commonly accommodate disc brakes.
Discernibly, drum brakes boast an extended lifespan compared to their disc counterparts.
Furthermore, drum brakes offer a more cost-effective solution regarding production expenses.
- Drum brakes are competent in fulfilling a vehicle's parking brake role.
- Disc brakes exhibit superior linear braking proficiency.
- Disc brakes demonstrate a more efficient ability to dissipate heat.
How To Remove Brake Drums and Replace Them
Here is how to remove brake drums and replace them.
1. Prepare the Car
Replacing drum brakes on an aged vehicle may emit harmful substances into the atmosphere, thus necessitating a mask and adequate ventilation while performing the task.
To guarantee the safety of others, it is critical to ensure that no one approaches the vehicle during the process.
To prepare your vehicle, you should:
Detach the wheel covers, loosen the lug nuts, and employ stands and a jack to lift and stabilize the vehicle. Disengage the parking brake to detach the brake drum.
2. Remove the Brake Drum
To access the brake shoes, it is necessary to remove the wheel and brake drum.
For front-wheel-drive vehicles, the brake drum may have a hub containing traditional cone bearings, which requires complete removal, including the spindle nut or axle nut used to secure the wheel to the axle.
Removing the brake drum involves loosening retaining screws or clips, sliding off the drum, and turning the star wheel on the drum adjuster after removing the rubber access port on the backing plate.
Brake drums may require a penetrant, hammer, or cut-off if they stick to the axle hub while pulling them away from the hub.
After removing the drum brake:
- Inspect the inner workings, such as shoes, springs, and wheel cylinders.
- Use brake cleaner to clean the entire assembly before disassembling any parts.
- Use a digital micrometer set to inches to measure the brake shoes' thickness.
- If less than 1/16th of an inch, replace them.
- Inspect the brake drums for grooving, cracking, or scoring, and check the wheel cylinders for leaks. If any leaks exist, replace the wheel cylinders.
3. Dismantle the Brake Drum
Utilizing needle-nose pliers, extract the shoe-retaining springs to dislodge the brake shoes.
Some automobiles utilize various springs to stress the brake shoes, in which case the highest spring must be removed to loosen the overall tension and make it easier to extract the remaining springs.
In addition, specific brake shoes are tensioned using pins and washers in place of springs, which can also be removed with needle-nose pliers. Extract the brake shoes after removing the springs, washers, and pins.
4. Take Out the Parking Brake Cable Retainer Clip
Extract the parking brake cable retainer clip using either a flathead screwdriver or pliers.
5. Put Back the Brake Shoes and Other Components
Thoroughly cleanse the backing plate with a brake cleaner solution. Insert the pin through the new shoe and reattach the parking brake retaining clip.
Proceed to install the adjusting screw assembly and screw spring. Secure the new brake shoes onto the hub with new pins and washers.
Restore the tensioning springs to their former positions to fixate the brake shoes securely.
6. Install the New Brake Drum
As a preliminary step to installing the new drum brake, make preparations such as cleansing the drum with cleaning spray, as specific drums might have a thin oil coating.
Once the drum is cleaned, glide it over the brake shoes and position it onto the hub.
If you face difficulty sliding the drum, attempt to adjust the brake shoes and refit the drum. You may adjust the brake shoes by turning the adjuster or using an adjuster tool.
Gradually adjust one increment until the drum can slide over the brake shoes and onto the hub appropriately without excessive resistance.
By this point, the drum brake should be completely reassembled. Ensuring that the brake drum is correctly affixed is essential, as any improper attachment may lead to problems.
7. Put Back the Wheels and Tires
Rotate the wheel and manipulate the backing plate to ensure the brake shoes contact the drum brake.
Fasten the wheel and tire securely using lug nuts.
When To Service your Drum Brakes
As brake drums and shoes are utilized, they undergo thinning, ultimately leading to wearing out and necessitating maintenance.
Similarly, wheel cylinders also wear out, thereby initiating leaks. These concerns collectively present the following issues:
- The vehicle may wobble or veer to one side when the brakes are applied from the back.
- The brake pedal may experience vibration or feel soft.
- The parking brake may feel slack or inadequately hold the vehicle in place.
- The brakes may squeak or produce a grinding noise when utilized.
