Your handbrake or emergency brake comes into its element when parking your car. Even though it doesn’t have as much clamping force as the power boosted foot brakes, it can keep your vehicle from rolling down the slope or moving with the engine on idle.
If your parking brake fails, your car could roll away – especially if it is manual and you park it in neutral.
Automatic transmissions have a pinion that locks the drivewheels with the car in drive. While this added security reduces the chances of your vehicle rolling off, the strain of engaging to hold your car without the help of the parking brake could wear down the transmission.
How Does the Parking Brake Work?
The traditional parking brake consists of a cable that bypasses the standard hydraulic brake lines and actuates brake pads independently. This happens when you apply tension to the cable by pulling the emergency brake lever in the cabin.
In cars with rear drum brakes, the tension in the cable pulls a lever in the drum that applies pressure to the brake shoes holding the vehicle in place.
Cars with disc brakes translate the tension force from the pulled cable into braking force using a corkscrew. The screw turns as you pull the hand brake lever pushing the pistons in the brake calipers. These will, in turn, engage the brake pads and hold your vehicle in place.
If your car has a push-button parking brake, there are no cables in the system. Instead, the car has actuators on the rear calipers. The type of actuator might vary from one manufacturer to another.
Either way, the result is electronically extending to engage the brake pads or retracting to release the rear brakes when disengaged.
How Do You Know if Your Handbrake is Broken?
The most notable sign that you have a faulty handbrake is your car rolling when parked with the emergency brake fully applied.
A typical parking brake has enough force to
- Stop your car from rolling even when parked on a slope
- Stop your car from moving when in gear but with the engine on idle
The speed with which your car rolls will determine where the damage is – and sometimes the extent of the damage.
If your car has sensors monitoring the efficiency and working of your handbrake, you will get a dashboard warning light if the eBrake’s power drops below the acceptable thresholds.
In other cases, your parking brake will fail by refusing to engage or disengage. It will remain stuck up or fails to go up. Sometimes, if it goes up, you will feel no resistance at all (in a cable-operated brake).
Types of Emergency Brakes
Before moving on to the common failure points in a handbrake system, we will first look into different types of parking brakes in the market. These are:
Center Lever Parking Brake
This is the most popular parking brake in cars with separate front seats. The handle sits between the two front seats by the center console.
Pull the lever up (entirely) to engage your emergency brake. To retract, press the button at the tip of the lever and push the entire stick back down.
Fun Fact: This hand-operated lever is so synonymous with the parking brake to the extent that people call it a handbrake (because you use your hand to operate it)
Foot Pedal Parking Brake
Some cars have the parking brake located in the driver’s footwell to the left of all driving pedals (around where you’ll find the dead pedal). Activate it by pressing it in until you feel or hear it click.
To disengage, you will have to step on it and depress it further. You will hear another click, and it will retract to the original up position once you let go with your foot.
Stick Lever Brake
Older cars with front bench seats (or no space on the center consolWhy is My Car’s Handbrake Not WorkingWhy is My Car’s Handbrake Not Workinge) stashed a stick lever under the instrument panel. In most models, you have to pull and turn the lever to engage the parking brake.
Disengaging is the other way round. Twist the lever to its original orientation and push it back into its sheath.
Push-Button Electric Parking Brake
Push buttons are getting common in modern cars. It is a great way to clean up the console without losing crucial controls.
The button is a tiny lever button similar to your window controls. You activate it by pulling it up or pushing it down, depending on your car’s design.
Common Failure Points in the Emergency Brake System
The failure points in an emergency braking system will change from one car to another depending on the braking system it uses.
We will split our failure points into:
- Common failures across the board
- Cable-driven parking brake failures
- Electronic parking brake failures
Common Failures Across the Board
Your parking brake can suffer from one of these problems regardless of how it works. These are endpoint problems that affect how braking force affects your rear wheels.
Worn out Rear Brake Pads
Your rear brake pads are your parking brake’s contact point. Its efficiency depends on how well they can clamp onto the rotors.
As brake pads wear down, they get thinner and need more travel to provide an equal clamping force. If this is the case, the preset travel on your parking brake system might not be enough to apply the correct clamping force to the rear rotors when you engage the handbrake.
You could also experience the same problem if you have glazed brake calipers, even if they’re not worn out.
Check out this post we did about brake pads to see more signs that they could be worn out and need replacement.
Faulty Rear Brake Calipers
Since the handbrake still uses your rear calipers, any damage that compromises their working could have an impact on your emergency brake’s operation.
This damage could be localized to the corkscrew the brake uses to engage the e-brake or even in the actual performance of the entire caliper.
You might not notice this when driving since most of the footbrake force goes to the front wheels, and some slight underperformance from the rear wheels might go unnoticed.
Damaged Rear Brake Shoes
If your car has read drum brakes, the handbrake engages the shoes in the drums to hold your vehicle in place when parked.
Drum brakes are susceptible to neglect. We don’t service them as often as we service disk brakes.
Over time, the brake shoes wear out and no longer make perfect contact with the drums rendering them useless. You could accelerate the damage if you ride your brakes or forget to disengage the parking brake a couple of times fully.
Worn out Read Brake Rotor
While brake rotors are solid metal chunks meant to last for decades, they could eventually wear out – mainly if you use very aggressive brake pads. After all, the friction gets to them even if it’s less profound than it is on brake pads.
Over time, the brake rotor could get thinner. The thinner the rotor, the more profound the impact of worn out brake pads will be. The tolerances will be way lower than the manufacturers had in mind meaning the handbrake won’t clamp as hard as it should.
Damaged Rear Brake Drum
Just like rotors in caliper rear brake systems, your brake drums are susceptible to age or general tear and wear. Any damage that reduces their girth or simply makes them disintegrate affects the integrity of your rear brakes.
The damage will be parking brake specific if it affects the lever that translates the tension on the brake cable to actual movement on the brake shoes.
This will, in turn, render your parking brake inoperable or less efficient.
Cable Driven Parking Brake Failures
A couple of things could go wrong with a cable-driven parking brake. Some are extreme and require part replacements, while others are minor and need a readjustment to get the brake working again.
A Broken Cables
A cable connects your handbrake lever to the brake drum or caliper at the rear axle. If this cable snaps, you will have no way to translate the pull energy you apply on the in-cab lever to the in-wheel levers.
In most cases, such damage will lose all feel on your parking brake lever. You won’t feel any resistance when you try to engage it.
Brake cables last for a lifetime. Howevhttps://avtotachki.com/en/kak-otregulirovat-stoyanochnyj-tormoz/how%20toer, malice or physical damage could severe them. Additionally, corrosion from offroading too much or driving in salty environments could accelerate rusting.
An Expanded or Loose Cable
Over time, your brake cable could expand due to stress and strain. While good quality cables stay within operational parameters for decades, brake cables going loose isn’t unheard of.
Many manufacturers prepare for this by giving you an adjustment knob that lets you fine-tune the parking brake cable’s tension.
The adjustment knob could be where the cable attaches to the lever in the cabin or at the point it connects to the attachment of the rear brake.
Pro Tip: A loose cable will still attach the rear brakes, but they won’t hold as firmly. The car might roll slowly. This symptom could also hint at worn out brake pads.
Cable Detached from Mounting Point
On rare occasions, the parking brake cable could detach at the point it attaches to the in-cabin lever or the lever on the rear axle. This is very rare. It will only happen if the cable was wrongly connected or if you used an incompatible aftermarket cable.
It will feel like your handbrake cable snapped. There won’t be any firm feedback when you activate the lever.
Failure Points in an Electric Parking Brake
Even though electric parking brakes (EPB) seem and sound fragile, they’re more resilient than traditional cable-driven brakes.
The working at the endpoint (at the caliper or drum level) is the same as traditional handbrakes.
You’ll only encounter differences in how the system generates the force needed to clamp down on your rear wheels.
How EPB Brakes Work
Here is a quick breakdown of how an electronic parking brake works
- Flip the parking brake switch to trigger engagement
- The switch sents some current through the car’s communication system (CAN bus) to an EPB module
- The module sends power (12V) via specific wires to brake actuators on calipers
- The polarity of the fed current will determine if the actuators engage the calipers or disengage them
Actuators are a combination of motors, driving shafts, and gearboxes. The nitty-gritty of the operation might vary from one manufacturer to another.
Some common fail points in such a system include:
A Blown Fuse
Since your eBrake system is essentially an electrical system, the wiring runs through a fuse in the fuse box.
This fuse has a specific rating and will blow if the system tries to draw more. Theoretically, this shouldn’t happen unless there is a problem with the wiring or the motor is faulty.
Check your fusebox and identify the EPB system fuse and confirm that it is still OK. If you find it blown, you could replace it and observe it. If it blows as soon as you engage the eBrake or after a few drives, there is a problem downstream, and you have to address it.
A Damaged Relay
In most systems, the EPB controller sends a signal to a relay that in turn sends voltage and Amps to the actuator motor to activate parking brakes.
If the relay is faulty, it won’t respond to signals from the controller. Your parking brake will be dead in the water. Consult your car’s manual to identify the location of the relay and confirm that it’s working.
A Faulty Switch
Assuming everything else is acceptable in the system, your parking brake can fail to work if the engage switch is faulty.
The parking brake switch has three positions. The neutral no-action position, and engage position, and disengage position. This is simple control, just like you get on your windows.
It is hard for them to fail but not impossible. If your switch isn’t making contact in one of the positions, it won’t send the right signals, and the parking brake sequence won’t engage.
Start by checking if the parking brake sends different voltage signals when you hold it up or press it down. Use a multimeter for accurate readings.
ProTip: Some EBP systems have a third Hold position that holds the car still in traffic, doing away with the need to put rest your foot on the brake pedal in start-stop traffic. It can also make hill starts smoother.
Damaged Wiring
The motor controlling your calipers at the car’s rear needs functional wiring to work – and so does the EPB control module.
If the wiring between these parts is damaged, your electronic parking brake might not work.
Luckily, all the wiring is neatly tucked away in a wiring loom that is hard to damage. However, you can quickly troubleshoot wiring if you have a multimeter and know where to probe.
ProTip: Before running any of these tests, ensure that your car has a well-charged battery and your main fuses are working. You can crank the car to be sure or turn it to Acc to have your accessories running.
- Identify the terminals to the actuator motor on your rear brake assembly
- Set the multimeter to 24V range and apply the probes to the terminals
- Have someone operate the e-Brake switch to activate the brakes
If the wiring is correct, you will get around 12V to the terminals. The polarity varies depending on whether the button was engaging or disengaging the brake.
If you get voltage and the brakes don’t engage, chances are the motor is the actuator system is the problem. You can narrow it down by listening to a motor whine. If you don’t hear it, the motor could be faulty. Try cleaning and reattaching the terminals to ensure it’s getting power.
If you don’t get voltage, a couple of things could be wrong.
- The eBrake switch could be faulty
- The wiring to EPB control module could be damaged
- The EPB module could be faulty
- Blown fuses
- A damaged relay
- Faulty general electrics
A Damaged Actuator
The actuator isn’t as simple as a corkscrew activated by tension from a handbrake cable. It has motors, gears and special calipers.
While these parts are built to last, neglect or no use for months on end could lead to damage.
The moving parts in the gear system could fail, making it impossible to move the pistons to the right place.
In other cases, the problem will be in the motor itself. Just like any other electrical part, the motor could fail over time. The whole system won’t work since the motor provides the torque it needs to work.
How Do I Know If My Handbrake Cable is Stretched?
A stretched handbrake cable will be loose. You will feel some play on the handbrake handle or foot pedal as you engage it. Instead of gradual firmness, the handle will start very easy before suddenly getting harder to engage.
Moreover, your parking brake might not grab well. This means your car will roll slightly on a steep incline or roll if the vehicle is in drive with the engine idling.
Luckily, you can use the tune nuts or knobs at the base of the handbrake lever or at the point the cable connects to the rear wheels to give sufficient cable tension.
How to Adjust Parking Brake Cable Tension (General Guide)
Here is a general guide to adjusting the brake cable tension. Remember first to check your brake pads and ensure they are as close to new as possible. Adjusting tension with worn-out pads will lead to extra tension when you replace the pads.
- Jackup the rear of the car so that both wheels are off the ground
- Raise your brake pedal about three clicks
- Use your manual to locate your adjuster lever or knob
- Loosen the clamping nut of the wire
- Try rotating the rear wheels by hand, listening for brake pads
- You should hear the pads barely scratching the rotors or drum
- If you can’t hear, then slowly use the adjuster knob to add tension to the cable until you can hear the pads scraping
- Tight the lock nut firmly and lower the car
- Test the efficiency of your parking brake
How Long Should a Handbrake Cable Last?
Typically, your parking brake should last for over the car’s warranty. While they might rust and fray in a mistreated car, chances are it will still hold until it gets physical damage.
If you live in a salty, humid, or rainy place, rust might make the cable susceptible to damage. Moreover, overtightening the cable could make it succumb to the extra tension.
How Do I Know if My Parking Brake Cable is Broken?
You can inspect the cable under your car. Most cables are attached to the bottom of the vehicle and are easy to track.
If you see the cable dropped or frayed, it is broken or in the process of braking.
Other ways to tell if its broken are:
- Not feeling any gradual resistance on the parking brake level throughout the engage cycle.
- You engage the parking brake and don’t see (or hear) the levers on the rear wheels move at all.
ProTip: Pulling the handbrake is not a test of strength. Please don’t overdo it. Pulling it beyond its top point will put extra strain on the car. However, this will not happen if your brake cable is tuned perfectly (to the correct tension with new brake calipers).
Can You Still Drive With a Broken Handbrake?
Yes. You can drive with a broken handbrake. You don’t need it until you are parking or need to stop your car in an emergency (when your foot brake fails)
However, you will have trouble parking on inclines. Your transmission will take extra strain holding the car in place when you put it in park for automatic transmission or in gear for manual transmission.
Check this too: Why Is My Car Losing Brake Fluid?
How Do You Unstick a Parking Brake?
Sometimes, your parking brake could fail when it is engaged. In this case, your rear wheels will drag slightly. You will need more revs to get your car moving, and if it is manual, it will be easier to stall it.
- Go under your car and physically retract the cable (pull it towards calipers or the drum)
- Loosen the tension nut to make it easier for the cable to release
- Try engaging and disengaging the handbrake a couple of times
- Call in a mechanic to open up the rear brakes and manually disengage
How Much Does it Cost to Fix a Parking Brake?
Prices will vary depending on the type of system, what you have to replace, and hourly rates from the mechanics in your area.
There is no right way to estimate the price without figuring out the problem with your system. If it’s just a loose cable, you could be looking for as little as $30 to tighten it or nothing if you do it yourself.
If it is a damaged actuator, you could be looking at hundreds of dollars in replacement caliper and system and another couple hundred in labor to get the new parts installed.