Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Hydraulic Brake Booster

brake booster

Bad or Failing Hydraulic Brake Booster Inspection

by a top-rated mechanic at your home or office

Hydraulic brake boosters are a type of brake booster found on many road going cars and trucks. Though not as common as conventional vacuum operated brake boosters, they serve the same purpose, to provide assistance to the brake system in order to reduce pedal effort and make brakes easier to operate. They differ from vacuum brake boosters, in that they operate using hydraulic pressure to assist the brakes, instead of engine vacuum. The boosters operate using hydraulic pressure generated by the vehicle’s power steering pump, or a dedicated hydraulic pump. Hydraulic brake boosters work especially well for vehicles equipped with diesel engines, where there is considerably less engine vacuum generated and therefore accessible to power accessories, in comparison to gasoline engines.

When the hydraulic brake booster fails or has an issue it can cause problems operating the vehicle’s brakes, which can become a safety concern. Usually a bad or failing hydraulic brake booster will produce a few symptoms that can alert the driver of an issue.

HAVE SYMPTOMS OF CAR TROUBLE?
Get an $80 diagnostic
by a top-rated mechanic at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

1. Reduced braking power

One of the first symptoms of an issue with the brake booster is reduced braking power. If there is any issue with the booster, or a compromise in the pressure of the system, the vehicle may experience reduced braking power. You may notice that the vehicle takes longer to come to a stop when the brakes are applied, and that the brakes do not respond as rapidly as they used to. Similar symptoms can also be caused by other issues with the vehicle’s brake system, so a proper diagnosis is recommended if you are unsure of the issue.

2. Brake pedal hard to press

Another common symptom of an issue with the hydraulic brake booster is a hard brake pedal. If the brake booster fails the power assistance for the brakes will be disabled and the pedal will become hard to press. A hard pedal will require significantly more effort to depress, which will result in reduced braking power and increased pedal effort.

HAVE SYMPTOMS OF CAR TROUBLE?
Get your car fixed at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

3. Fluid leaks

Another symptom of an issue with the vehicle’s hydraulic brake booster is fluid leaks. If any of the seals or hoses that are a part of the hydraulic brake booster system wear out or rupture, they may leak fluid. Depending on the severity of the leak this may produce drips or puddles of hydraulic fluid beneath the vehicle. Any leaks present in the hydraulic brake booster system should be addressed as quickly as possible, as they will eventually compromise the operation of the system, once the fluid level drops low enough.

A properly functioning hydraulic brake booster will make it easy to operate the brakes without the need for excessive force, and can cause braking, and therefore safety issues with the vehicle when it has problems. If you suspect that your vehicle may be having an issue with the hydraulic brake booster, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the booster should be replaced.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...


Related questions

Q: Damage to my brake booster

Brake fluid in the brake booster is definitely a sign of a leaking master cylinder as you know. Additionally, brake fluid in the brake booster will also cause deterioration in the diaphragm resulting in failure leading to vacuum leaks and...

Q: Got hit by the gas tank on a 2000 nissan maxima now axel looks bent. What else might be broken

Hello, thank you for writing in. In the area of the fuel tank and axle, there are likely fuel and brake lines to be concerned about. This is in addition to the components related to the wheel, axle, and fuel...

Q: I poured seafoam in my brake booster I thought it went there instead of in the vacuum

Hello, the brake booster assembly will have to be replaced. There are rubber diaphragms that degrade from seafoam. The hissing sound is a vacuum leak with the booster. I recommend having a certified YourMechanic technician come to your location to...