Before you begin, it’s important to be familiar with your specific parking brake system. While all systems accomplish the same thing, the designs will vary from manufacturer to manufacturer. Some systems will have two or three points of adjustment, and others will have only one. Identifying the components of the system you have is important to a successful parking brake adjustment.
The parking brake shoes are part of a larger system known as the drum brakes. Drum brakes have been in use on automobiles for over 100 years. The shoe is the star of the drum brake system. It provides the friction against the drum that stops your car when you step on the brake pedal. Drum brake systems are only used on the rear wheels nowadays, as they are not as efficient and require more maintenance than the modern disc brake system. Even so, they are superior as a parking brake and remain in use for this reason.
The parking brake system is integrated into the drum brake system by the use of cables reaching to the front of your vehicle. The cables are attached to a lever that you step on or pull. When this lever is engaged, it expands the brake shoes in the drum and wedges themselves in place. This wedging creates a strong force that will not allow the rear wheels to spin.
The terminology describing this system is often confusing - sometimes the brake is called an emergency brake, and other times it is called the parking brake. Some will argue this point, but at the end of the day, this system can be used for both. If the hydraulic system of your disc brakes were to fail, the mechanical connection via the drum brake cables can be engaged to slow your vehicle to a stop, hence the term “emergency brake” or “E-brake.” At the same time, this system is used to keep a vehicle from rolling away while parked. This is particularly necessary with vehicles that have manual transmissions.
Parking brake shoes are designed to self-adjust, but the self-adjusting system can often fail. The brake shoe is housed in the drum and experiences lots of heat and brake dust that eventually leads to wear and tear. Eventually, it requires manual adjustment, either because the brake shoes need to be replaced, or because the self-adjusting mechanism has become gummed up or worn out. This tutorial will instruct you on both brake shoe and parking brake adjustment, since they are integrated components and should be serviced at the same time.
Part 1 of 4: Lifting your vehicle
- Brake spoons
- Floor jack
- Jack stands
- Open end wrenches
- Small pry bars or large flat head screw drivers
- Wheel blocks
Step 1: Park the car on a flat, level surface, and loosen the tire lug nuts. Place the wheel blocks around the tires. Then, loosen the lug nuts so you can take the wheel off later if need be.
Step 2: Locate the lifting points for your vehicle and raise the vehicle with your floor jack. Kneel down and look under your car at the point where the front wheels and the front passenger or driver door meet.
Usually, there is something there that makes the lifting point obvious, but not always. If you are unsure of where to properly lift your vehicle, you will need to refer to your owner's manual or a shop manual.
Place the floor jack under the lifting point and carefully lift the vehicle until the jack stands will fit underneath.
Step 3: Place the jack stands under the car. The best spot to place jack stands under your car is at a frame section.
Before placing a jack stand, be sure the spot you choose to place the jack stand is solid enough to support the weight of the entire car. If you can’t find a frame section to place the jack stand, you can place it under a solid rear axle, a trailer hitch or the lip that runs from the front wheels to the rear wheels under the doors.
With your jack stands in place, slowly lower the car onto the stands and remove the floor jack.
Warning: Do not use a floor jack to support the car; it is only for lifting. It is not safe to be under the car without a jack stand.
Note: Refer to your owner’s manual if you are not certain about jack stand placement.
Part 2 of 4: Relaxing the parking brake cables
Step 1: Locate the brake cable adjuster. The brake cable adjuster is usually located in one of two different places: either under the car about midway between the front and the rear, or attached to the parking brake lever.
The parking brake lever can be foot-actuated and mounted to the driver's left, or hand-actuated and mounted at the driver's right in the center console. These are by far the most common placements for brake levers, but some manufacturers will put them in other areas.
Step 2: Turn the self-adjuster counterclockwise. Most of the time - but not always - you will want to turn the nut counterclockwise to provide slack in the cable system.
You do not want the cables to become slack and loose. You only need enough slack in the cable system so that they are not pulling on the rear shoe parking brake adjuster.
- Note: If this step is not performed, you may not be able to adjust the brake shoes properly.
Step 3: Refer to your shop manual for auto-adjuster methods, if needed. Most auto-adjusters are integrated into the lever assembly. Some are completely maintenance-free, and others require resetting when adjusting the parking brake.
Each one will be different so refer to the appropriate shop manual for location and procedures.
- Note: Auto-adjusters are not very common.
Part 3 of 4: Adjusting the parking brake shoes
There are three main types of parking brake systems in use today.
- The most common is the brake shoe system that has been in use for decades.
- Rear disc brakes with a drum cast into the rotor. The parking brake part of this system is a drum brake system.
The disc brake only system. The only part of this procedure that applies to disc-only systems is the adjustment of the cable system.
Warning: Improperly adjusted parking brakes can lead to premature shoe failure, drum or rotor warping, and the distinct possibility of a fire at the rear wheels. The vehicle may also cease moving forward. Keep in mind, if you are new to this sort of repair it will take significantly more time to accomplish in comparison to a technician with years of experience. But don’t let that discourage you. Give yourself plenty of time and manage your frustration.
Step 1: Remove the wheel, if needed. Sometimes the wheel must be removed in order to access the star adjuster.
This adjuster may be accessible through a hole in the brake drum backplate.
Step 2: Shorten the star adjuster by turning it in the correct direction. You will need to turn the star adjuster in a different direction depending on what side of the car it is mounted on.
Just a few clicks should do the job here.
Check your owner’s manual if you cannot tell which direction tightens the adjuster.
A flat head screwdriver or brake spoons can be used to turn the star adjuster. Brake spoons have bends in them of various types that allow you to turn the star adjuster in hard-to-reach spaces.
Step 3: Center the brake shoes. Once the star adjuster has been shortened, you may need to move the shoes around to fit the drum on.
Brake shoes float on the backing plate so they can center themselves in the drum. With the drum off, shoes can be moved side to side and up and down.
Often a couple of large flathead screw drivers will work, or maybe just your hands. Depending on the kind of vehicle you are working on, using a couple of small pry bars may be the easiest option if you have them available.
Step 4: Install the brake drum. Install the drum over the brake shoes and use two lug nuts to make sure it is flush with the wheel hub mounting.
If it isn’t square on the hub, you won’t be able to achieve a proper shoe adjustment.
Step 5: Turn the drum. Turn the drum and listen for a rubbing sound. It should be consistent and the drum should turn easily.
- Note: If you have a rear wheel drive vehicle, this step is a bit more difficult. As well as turning the drum, you will be turning the rear drive line and both the rear wheels. This means you will need to have the vehicle in neutral and the front wheels will need to be blocked to keep the vehicle from rolling away while you are working on it. In addition, because you will be turning both axles, you will have only one drum installed while turning and adjusting. If you have both drums installed on a rear wheel drive vehicle, you will not know which side is creating drag.
Step 6: Expand the star adjuster. Remove the drum and expand the star adjuster as needed. Re-install the drum with two lug nuts.
- Note: Drum brakes have a backing plate adjustment hole on the backside, but it can be cumbersome to make large adjustments. At this point, it will likely be most efficient to remove the drum to turn the star wheel until you hear rubbing when turning the wheel. The backing plate adjustment hole should have a rubber plug installed in it. You will remove it to access the star adjuster with the brake spoons for fine tuning.
Step 7: Center the shoes in the drum. Once you hear the rubbing of the shoes against the inside of the drum on both sides, you will need to step on the brake pedal very hard. This will continue the process of centering the shoes in the drum.
- Warning: Be sure both drums are installed before stepping on the brake pedal. If the drums are not installed, you will push the pistons in the wheel cylinders out of their bores and create a large brake fluid leak.
Step 8: Expand the star adjuster more, as needed Continue expanding the star adjuster by removing the drum or utilizing the backing plate adjustment hole.
Step 9: Repeat Steps 4-7 until proper shoe-to-drum pressure is achieved. The goal of adjusting a drum brake system is for the shoes to lightly drag on the drums when the drums turn. It should not be difficult to turn the drums by hand.
Larger vehicles may be difficult to judge because of their larger mass and increased contact area. If the shoes are adjusted too tightly in the drum, this will result in excessive heat that can warp the drums, cause brake fade, and possibly even a fire. As long as you can easily turn the drums with a light dragging sound from the shoes, everything will be fine.
Part 4 of 4: Adjusting the parking brake cables
Step 1: Install the rear wheels. Mount the rear wheels, then install and tighten the lug nuts until snug.
Do not torque the lug nuts while the vehicle is still lifted.
Step 2: Turn the cable adjuster nut clockwise. Go back to your brake cable adjuster nut that you loosened earlier.
Turning the nut on the cable adjuster clockwise will shorten the cable assembly, making it taut. Do this in a few increments at a time, as you don’t want to tighten the cable so much that it makes the shoes drag against the drum.
You only want the shoes to engage when the parking brake lever is engaged.
Step 3: Engage the brake lever. Pull or step on the parking brake lever to engage the brake shoes.
The lever should stop firmly about halfway through its travel.
If the lever goes all the way to the floor, or pulls up really high in the case of a hand-actuated lever, you should turn the cable adjuster nut more.
Step 4: Check for correct parking brake adjustment. Attempt to turn the rear wheels, if you have a rear wheel drive vehicle.
You should not be able to turn them at all. Remember, the parking brake needs to keep your heavy car from rolling. If you can turn the wheels, then you will need to tighten the cables more - but you don’t want to tighten them so much that the shoes will drag heavily in the drums.
Step 5: Release the parking brake lever. There shouldn’t be any extra drag on the rear wheels beyond the rubbing from the brake shoe adjustment. If there is an increased drag, you will need to back off the cable adjuster until the only drag you feel is created during the shoe adjustment.
Step 6: Lower the vehicle and go for a test drive. Place the floor jack back under the lifting point and raise the car up enough to remove the jack stands. Carefully lower the car back to the ground.
Make sure to torque the lug nuts on any wheels previously removed to the manufacturer’s specifications.
- Warning: Until you are certain that you have correctly adjusted your parking brake shoes, test drive your vehicle in a safe area such as a deserted parking lot.
It can be very easy to become confused when adjusting your drum brake shoes and the parking brake cables. There are many different brake system designs on the road today. For this reason, it is highly advised that you identify each component of your specific system before you begin. In every case, the shoes should be adjusted first, followed by the parking brake cables.
The main indicators of a properly adjusted drum and parking brake system are the brake pedal and the parking brake lever. If the brake pedal goes further towards the floor than usual, this means the system components have to travel too far before the shoes are completely contacting the inside of the drum. Centering of the brake shoes is paramount to a successful brake shoe adjustment.
The same standard should be applied to the parking brake lever. If it travels to the end of its range, the shoes or the cables are not adjusted correctly, and each step should be revisited to find where extra play in the system exists. In both cases, the goal is for the shoes and or cables to travel as little distance as possible before they begin to slow or lock the wheels.
If you have any difficulty during the process of adjusting your parking brake cable, adjusting your parking brake shoes, or if you find that your parking brake won’t function correctly after making adjustments yourself, don’t hesitate to contact a certified mechanic. One of our mobile mechanics here at YourMechanic will be happy to come out to your home or place of business to get your parking brake working again.