What Causes Brake Imbalance? (+Symptoms and How to Fix)

Typically, you’d want your car’s brakes to apply balanced stopping force when stepping on the brake pedal.

But what if your vehicle pulls to one side when braking?

Then, you likely have a brake imbalance.
When your car has a brake imbalance, each brake does not apply the same force.

Does an uneven brake pad cause it?
Or is it worn brake discs?

Either way, if your car has braking problems, you must figure out the issue before it leads to complete brake failure. In this article, we’ll cover the prominent symptoms of brake imbalance, what causes this issue, and a few fixes to help you out.

Let’s jump right in.

2 Symptoms of Imbalanced Brakes

The symptoms of brake imbalance can vary in severity, depending on how long the issue has persisted.

There are two main symptoms that you will experience if your brakes are imbalanced:

1. Car Pulling to One Side When Braking

The most apparent symptom you’ll notice if your brakes are imbalanced is that your car will pull to one side when stepping on the brake pedal, regardless of the direction you turn the steering wheel.

Naturally, your vehicle will pull towards the side where the brakes apply more stopping power.

Can this be dangerous?
Yes. In cases where brakes are severely imbalanced, you may lose complete control of your vehicle, especially when moving at higher speeds. This could force you to use the parking brake, which isn’t as controlled as the foot brake and not advisable at speed.

2. Brake Fade

No matter the cause of imbalanced brakes, this fault will cause brake fade. “Brake fade” is a more straightforward way to say you are losing braking force.

Imbalance causes the brakes to work much harder to bring the car to a stop — as there’s an uneven distribution of force generated to slow down the load. This also causes the working brakes to fade much faster.

This can be scary, as no one wants brake failure when stopping the car!
If you notice these symptoms when driving, either a sideways or front to rear brake imbalance, you’ll need to resolve the issue as soon as possible.

Let’s look at some common causes of this imbalanced brake failure.

5 Common Causes of Brake Imbalance

Problematic braking system components typically cause brake imbalance.
Here are 5 reasons you could be experiencing brake imbalance:

1. Uneven Brake Pads

As a brake pad ages, it starts to wear from extended use. The most common cause of brake imbalance is when one or more brake pads wear faster than others, causing the mirroring components to be uneven.

This variation in pad thickness and integrity typically results from the brake rotors chewing away at the pad material as the parts come into contact during deceleration.

Depending on the difference in thickness between the brake pads, a lack of consistent friction can cause sideways or front to rear brake imbalance. Regular brake maintenance can slow down pad erosion.

2. Worn Brake Discs

Stepping on the brake pedal pushes fluid through the brake lines of the braking system. This causes the brake pads to squeeze onto the brake discs, creating friction that slows down the car.

It’s only natural that the heat generated by this friction will cause the brake discs to warp and wear as time goes on. Worn-out brake discs are another major cause of brake imbalance.

3. Worn Drum Brake Shoes

Brake shoes perform a very similar function to brake pads, except that they’re installed in a different brake system (drum brakes).

When a driver applies the brakes, the drum brake system pushes the brake shoe outward against the drum, causing friction and slowing down the vehicle. Like brake pads, brake shoes will become worn over time, causing brake imbalance and failure to stop promptly.

4. Damaged Brake Caliper

A caliper is the component that squeezes the pads against the brake rotors to create stopping power. There are generally two types of brake calipers:

Single piston: A single caliper piston is often used on a rear caliper because less braking force is needed.
Dual, 4, or 6 piston caliper: These apply hydraulic pressure from both sides of a caliper. Most front brake calipers contain dual pistons.

Either way, when the driver presses on the foot brake, the brake hose transmits hydraulic pressure to the brake calipers. The caliper piston is then moved forward, pinching the rotors between the brake pads.

A damaged caliper will not retract the piston automatically when the brake pedal is released. This could cause the vehicle to pull to one side when braking as the brake caliper is still engaged.

5. Air Pressure Imbalance

Trucks are no strangers to brake imbalance problems. A pneumatic (air pressure) imbalance most commonly occurs in a truck with air brakes or trailer brakes.

When the air system in a truck delivers improper pressure to the brake line and chambers, some air brakes will work harder than others to bring the large vehicle to a stop. In more severe cases, some brakes may even lock up faster than others, which is a symptom of severe brake imbalance.

Now, let’s look at a few less typical reasons for brake imbalance that you should be aware of.

3 Less Common Causes of Brake Imbalance

We’ve covered the most common culprits of brake balance, so let’s go through a few out-of-the-ordinary causes:

1. Incorrectly Adjusted Brakes

Incorrectly adjusted brakes aren’t a problem many drivers have to deal with, and it isn’t a direct cause of brake imbalance.

However, incorrectly adjusted brakes often cause components, like the axle, brake pads, discs, or rotors, to wear out at different speeds. This will lead to an imbalanced system that needs to be readjusted by a mechanic.

2. Failing Proportioning Valve

The proportioning valve plays the most crucial role in achieving brake balance.

This valve connects the master cylinder to the rest of the braking system and is necessary for balancing any front to rear wheel bias for alignment. It’s a spring-loaded component that activates as brake fluid pressure builds during deceleration — creating a good load balance between the front and rear brakes.

A properly working proportioning valve ensures your rear brake doesn’t lock up when pressuring the brake pedal. When the proportioning valve isn’t in good condition, your rear brakes may receive too much pressure, causing an imbalance in the front to rear wheel alignment.

3. Incorrect Gross Vehicle Weight Rating

The gross vehicle weight rating (GVWR) is to test your vehicle’s maximum body weight. This rating considers all vehicle parts, including the tires, chassis, body, auxiliary equipment like the steering wheel and hand brake, and payload weight when dealing with trucks.

Vehicles that exceed the weight rating test will experience dramatic changes in performance, including poorly adjusted tires and a wheel imbalance in the braking process (from uneven loads).

We’ve now covered common and uncommon causes of front and rear brake imbalance.

But how do you fix this brake problem?
Let’s find out.

How to Fix Brake Imbalance

Since brake imbalance is the fault of many different factors, here’s how to resolve each major issue individually:

If the issue relates to worn-out braking components, it’s recommended that you purchase replacements instead of seeking out a repair. Be sure to take your car in for regular brake maintenance to keep components in good condition.

A mechanic can resurface parts like brake discs that have become warped or uneven. Whether this fix can be applied depends on how much surface needs to be reshaped.

The brake proportioning valve can be reset. A mechanic will loosen up all of the braking components surrounding the axle, valve, and wheel, readjust the valve according to the owner’s manual, and re-tightening the loose components.

Note: Unless you know your way around the internal parts of a car, you should seek the help of a professional mechanic.

Closing Thoughts

If it’s clear that you’re dealing with an issue relating to your car’s brake system, like brake imbalance, you should seek out help immediately.

An imbalance will decrease the braking force of your car and could cause you to lose control when applying deceleration — which could be very dangerous. No one wants to resort to the parking brake to stop the car.

But who can fix a brake problem like this?
Try AutoNation Mobile Service.

AutoNation Mobile Service is a mobile mechanic service that brings expert technicians right to your driveway. We are available seven days a week and provide a 12-month | 12 000-mile warranty on any and all repairs!

Contact AutoNation Mobile Service to easily book a braking service if you’re worried that your brakes are imbalanced!