Effects of Driving With the Parking Brake On

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on February 25th, 2024

Reading Time: 6 minutes
Summary
  • The parking brake makes sure that your vehicle doesn’t move while it’s parked.
  • If you drive with the parking brake on, you’ll wear the linings out very rapidly unless your vehicle has electric parking brakes, which typically release automatically.
  • When you drive with the emergency brake on, your vehicle will either move sluggishly or refuse to move at all.

Leaving the Parking Brake On When You Drive

Anyone can err by driving with the parking brake still on. An abrupt emergency might have forced you to transfer to a different vehicle that you’re unfamiliar with. In your haste to make up for lost time, disengaging the parking brake might have slipped your distracted mind. Or you didn’t put sufficient force into the control lever or pedal when you got ready to leave the parking slot, leaving the brake engaged when you stepped on the gas.

Whatever the reason for your mistake, it helps to know what happens when you drive with the parking brake on. This way, you can stay on top of potential repair jobs.

What Is the Parking Brake?

The parking brake makes sure that your vehicle doesn’t move while it’s parked. In older models, it also serves as a backup if the service brake fails, which is why it’s also called the emergency brake.

While the emergency brake runs on the same friction-based principles as the service brake, it lacks the latter’s stopping power. That’s why it’s simply a parking brake in later models.

In most vehicles, the parking brake latches on to the rear wheels. Since it’s normally only used to secure a parked vehicle, there’s no need for a connection with the front wheels.

On most vehicles, engaging the parking brake will turn on a warning light on the dashboard. The light will remain illuminated as long as the parking brake stays on.

What Happens if You Drive With the Parking Brake On?

It depends on the type of parking brake, but you’ll wear the linings out very rapidly regardless of what kind of parking brake you have, with the exception of electric parking brakes, which typically release automatically when the vehicle is placed in gear and your foot is on the service brake.

When you engage the parking brake, most typically use cables to mechanically press the brake pads into the rear wheel’s brakes, which are either drum-type or rotor-type. Physical contact between the pads and brakes generate friction, which slows down the wheel’s rotation.

If the brake pads remain pressed into the rotating drums or rotors, they’ll produce higher amounts of friction and heat.

Diagram showing operation of parking brakes | Image Source: Richard McCuistian.
The kind of rear caliper pictured here has a built-in mechanism for applying the service brake pads on rear disc brakes. | Image Source: Richard McCuistian.

In extreme cases, driving a long way with the park brakes engaged can cause the fluid to boil so that there’s air in the lines and very little braking. This is particularly true with drum brakes.

One very common style of parking brakes is seen in this photo where the service brake rotor includes a small park brake drum with a miniature set of brake shoes. These are easy to replace while you’re doing a rear brake job. | Image Source: Richard McCuistian.

How Does Driving With the Emergency Brake On Affect Your Vehicle’s Handling?

Have you ever hit the gas and brakes simultaneously by accident? Depending on how forcefully you pressed the gas and brake pedals, your vehicle either moved sluggishly or didn’t budge an inch.

Something like this can happen when you drive with the emergency brake on.

Usually, with drum-style parking brakes, you might not notice that the park brakes are still applied while backing up, but you may realize something is wrong when you start to drive forward.

If you haven’t used the parking brake in a long time and another driver applies it, the park brake indicator switch may have contacts that are corroded so that the red brake light doesn’t illuminate even though the parking brake is applied.

What Happens to the Parking Brake’s Components When You Drive With It On?

Although its original incarnation served as the service brake’s backup, the modern parking brake only stops a parked vehicle. Using it outside of its intended purpose will wear out its components faster or even damage them, necessitating their repair or replacement.

Brake pads are vulnerable to premature wear and tear. The excessive heat produced by the wheels spinning with the parking brake on might form glazing on the pads’ surface.

A glazed surface reduces the friction applied by the brake pad on the brake drum or rotor. This will reduce the strength of the pad’s grip on the brake’s surface. By making the brake more slippery, glaze reduces the system’s ability to keep the vehicle halted.

Driving a Front-Wheel Drive Vehicle With the Parking Brake On

Most cars and trucks use either front-wheel drive (FWD) or rear-wheel drive (RWD). Depending on your vehicle’s drive system, different issues can happen if you drive it with the parking  brakes still on.

FWD cars and trucks transmit the power generated by the engine to their front wheels. If you try to drive a FWD vehicle with the parking brake on, the rear wheels will cause drag. This reduces acceleration, although the emergency brake isn’t strong enough to completely stop your vehicle unless you’re moving at the slowest speed. Thus, the proper name for this is the “park brake.”

Remember how the parking brake connects to the rear wheels? Since FWD vehicles don’t supply power to those wheels, they won’t rotate as long as the brake stays on. Think of it as the vehicular equivalent of digging your heels into the ground to resist someone pulling you.

On the upside, you’ll quickly notice there’s something off if you drive a FWD vehicle with its parking brakes on. You have a better chance of stopping your vehicle and discovering your mistake before the brakes take more serious damage. Note, however, that this depends greatly on the size and weight of the vehicle.

Driving a Rear-Wheel Drive Vehicle With the Parking Brake On

RWD vehicles have it worse than their FWD counterparts. The former drive their rear wheels, the same pair that the parking brake tries to stop rotating.

At all but the lowest revolutions per minute, the RWD vehicle’s engine drives the rear wheels too fast for the parking brake to stop. You might not even notice the slight drop in acceleration at really high speeds.

As mentioned earlier, driving with the parking brake on for long periods or at high speeds will wear out its components faster. It might also affect the rear wheels and nearby parts exposed to the intense heat made by the brake pads gripping the spinning wheels.

If you accidentally drove with the parking brake on, you should check the wheels and brake afterward. Bring your vehicle to a trusted auto repair shop as soon as you can for a more thorough check.

Where to Get Replacement Parking Brake Parts for Your Vehicle

Parking brake parts like the cables and shoes can wear out over time. If you find any indication that one of these parts has failed, replace the faulty part before driving your vehicle. Luckily, you can get high-grade replacement parking brake cables, parking brake shoes, and more from CarParts.com.

Enjoy secure online shopping for parking brake cables, parking brake shoes, and parking brake levers at CarParts.com. Plug the details of your car or truck into our website’s integrated vehicle selector to search our catalog of parts and accessories for the products that fit your application. Order with a few clicks or taps for stress-free shopping online. Our strategically located warehouses quickly ship our on-hand products, so you can expect your order to arrive in just a few business days. Furthermore, we source our parking brake cables and parking brake shoes from veteran manufacturers, so you know you’re getting the most bang for your buck.

Make CarParts.com your one-stop shop for competitively priced, quality cables and shoes for your car’s parking brakes. Don’t miss out on the great deals on parking brake cables and parking brake shoes today!

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician