Symptoms of a Bad or Failing Brake Booster Vacuum Pump

A brake booster vacuum pump is a component found on the braking system of many modern diesel vehicles equipped with diesel engines. Due to their operational nature, diesel engines generate considerably less manifold vacuum than gasoline engines, and as a result, require a separate pump to produce the vacuum required for the booster to operate. It is responsible for generating vacuum for the vehicle’s brake booster so that the power assisted braking will work.

As the vacuum pump is what allows the vehicle to have power assisted braking, it is a very important component to the overall safety and handling characteristics of the vehicle. When the pump does fail or begins to have problems, usually a few symptoms will be produced that can alert the driver that a potential problem has occurred and should be serviced.

Stiff brake pedal

One of the first symptoms of a potential problem with the brake booster vacuum pump is a stiff brake pedal. The brake booster vacuum pump supplies the vacuum required for the power brake booster to work. If it fails or has a problem, the vehicle will be left without assisted braking. Without the brake booster, the brake pedal will be stiff and will require considerably more effort to stop the vehicle.

Intermittent power brakes

Another less common symptom of a problem with the booster vacuum pump are power brakes that function intermittently. As most brake booster vacuum pumps are electric, if there is any problem with any of the wiring or internal components, this may cause the pump to come on and off intermittently. Most pumps are designed to run continuously to provide a constant supply of vacuum so that the power brakes will work at all times. If you find that the brakes are assisted some times and not others, then the pump may not be functioning correctly.

The brake booster vacuum pump is an important piece of the power brake system, as the power brakes cannot function without the vacuum it supplies. For this reason, if you suspect that your brake booster vacuum pump may be failing, have the vehicle’s brake system diagnosed by a professional technician, such as one from YourMechanic. They will be able to determine if the car needs a brake booster vacuum pump replacement, or make any other repairs if needed.


Next Step

Schedule Brake System Inspection

The most popular service booked by readers of this article is Brake System Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Brake System Inspection reviews

Excellent Rating

(334)

Rating Summary
309
14
4
1
6
309
14
4
1
6

Jesse

17 years of experience
127 reviews
Jesse
17 years of experience
Jaguar S-Type V8-4.2L - Brake System Inspection - Palm Coast, Florida
Jesse showed up for the appointment timely and ready to work. He was polite and professional and competent. He took sufficient time to inspect the vehicle and explained in layman's terms any problems and whatever corrective work that might be required. I highly recommend Jesse and hope to have him service my vehicles again in the future if needed.
Ford Escape - Brake System Inspection - Daytona Beach, Florida
Jesse arrived on time after sending notice 15 mins prior. A true professional Jesse got right down to business. He started his inspection work right away and did a thorough professional job and determined the solution to his findings. I am very pleased. He is a true expert mechanic.

Johnny

34 years of experience
392 reviews
Johnny
34 years of experience
Toyota RAV4 L4-2.4L - Brake System Inspection - Sacramento, California
Johnny arrived early which was great, he performed the inspection in less than half an hour, and gave us a complete quote for all items needing attention, including the brakes as our main concern. Johnny is fast and efficient so I scheduled the work done by him.
Ford Escape - Brake System Inspection - Sacramento, California
The convenience is worth the cost. I was also tired of the dealership not really caring about my old car. Last couple of times I had to wait well over an hour to get my car after the dealership said "It's ready!". They also wouldn't fix the things I asked saying they didn't have time and I need to come back.

Luis

30 years of experience
119 reviews
Luis
30 years of experience
Honda Accord V6-3.0L - Brake System Inspection - Northbrook, Illinois
He's excellent. On Time, honest and all repairs done quickly and correctly. Book him if he's available!

Christopher

16 years of experience
246 reviews
Christopher
16 years of experience
Nissan Sentra L4-2.0L - Brake System Inspection - Charlotte, North Carolina
Very informative and made sure to clarify on what he spoke on so that I understood what was happening with my car

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

Related articles

How to Replace a Cruise Control Brake Release Switch
The cruise control is turned off by the brake release switch which fails either when the cruise control does not deactivate or does not set properly.
How to Replace an Exhaust Gas Recirculation (EGR) Vacuum Modulator
The EGR vacuum modulator meters the EGR valve in some car systems. Some signs of a failing EGR vacuum modulator include stalling and a rough idle.
How to Replace a Car Combination Valve
The combination valve balances your brake system. If broken, it should be replaced to ensure a safe driving experience.

Related questions

Whistling noise when braking and accelerating
Hello. If the noise occurs when applying the brakes and not moving then you may have a failure in the brake assist. If it only occurs when the vehicle is moving then you may have a failure in one of...
Went to get inspected and the Nissan garage said I had rusty rotors and the only fix is to replace them along with new brake pads.
The rusted rotors are from not driving the vehicle that often. When the rotors get wet and sit for a few days they will get rusted, even when new. If you are getting a grinding noise then the work will...
Brake sinks slowly while at stop
The most common cause for the brake pedal to sink slowly to the floor will be the brake master cylinder internal pressure cup failure. The seals may be worn or sludged up from old dirty brake fluid. I have seen...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com