You can fix the “Service Brake System” by replacing the faulty brake booster, refilling the brake fluid, and replacing contaminated brake fluid. You can also fix this issue by replacing worn-out brake pads and the faulty brake pressure sensor. If you get this error message you can still continue driving, but you should fix it as soon as possible.
Still not sure how to fix Service Brake System? Read this article to learn more.
Key Takeaways
- A step-by-step guide to the reasons, symptoms, and solution
- Safety judgment of driving with the service brake system error code
- Tips to avoid the service brake system error message
Fixing The Service Brake System Error: Reasons & Solutions
To fix the “Service Brake System” error message, simply follow this quick and easy guide:
| Reason | Symptom | Solution |
| Faulty brake booster | – Very hard brake- Whistling – Engine stalling when braking | Replace the faulty brake booster |
| Low brake fluid | – Low fluid level in the reservoir of the master cylinder | Add brake fluid to the master cylinder |
| Contaminated brake fluid | – Discolored brake fluid – A burning smell when applying the brakes | Remove the contaminated brake fluid and replace it with new brake fluid |
| Worn-out brake pads | – Loud grinding noise when braking | Replace the worn-out brake pads |
| A bad brake pressure sensor | – Error codes related to the brake pressure sensor | Replace the bad brake pressure sensor |
Still not sure how to fix the service brake system? Do not worry. Read the subsequent sections to get a more detailed solution to your problem.
How to Fix The Service Brake System? An In-Depth Guide
How you can fix the “Service Brake System” error will depend on the cause of the issue.
The Faulty Brake Booster
Symptom
Some common symptoms of a bad brake booster include
- Difficulty in applying the brakes
- The increased stopping distance of the car
- Decreased stopping power of your vehicle
- Stalling of the engine
- Check engine indicator light glowing
- A whistling sound when you apply the brakes
- A leaky brake booster or a leaky vacuum hose.
- Reduced or no brake assist.
To check if the brake assist is functioning properly, follow these steps:
- Drive your car for 5 minutes.
- Park the car.
- Let the engine run idle for another 30 seconds. Do not press the brake pedal during this time.
- Shut down the engine by turning the key in the ignition barrel.
- Immediately press the brake pedal multiple times and count the number of presses it takes for the pedal to become stiff.
If the brake pedal becomes stiff before 3 presses, then you have a faulty brake booster.
- Starting the engine does not soften the brake pedal.
Solution
If your brake booster is faulty, then you need to replace the brake booster. On the other hand, if you have a leaky vacuum hose, then you will need to replace the hose instead. To identify whether it is the vacuum hose that’s leaky or the brake booster, follow these steps:
- Mix water and dish soap in a spray bottle to form a soap solution.
- Start the engine of your car.
- Open the hood of the car.
- Locate the brake booster of your vehicle. It is a large round-shaped device that lies between the brake pedal and the master cylinder.
- Spray the soap solution all over the brake booster.
- Check if water gets sucked in at any part of the brake booster.
- Then spray the soap solution on the vacuum hose that connects with the brake booster to identify if the hose is leaking.
- Check for water getting sucked in around the vacuum hose.
If you find any spot on the brake booster where the water is getting sucked in, then the brake booster is leaky. However, if you find that the water is getting sucked into the vacuum hose, then you have a leaky vacuum hose. If you do not have any leak but you have the above symptoms, then you still have a faulty vacuum booster.
Depending on whether you have a faulty brake booster, a leaky vacuum hose, or both, follow these steps:
Replacing A Faulty Brake Booster:
Tools Needed:
- A new brake booster
- A ratchet
- A socket set
- A shop towel
- Brake fluid
- An adjustable wrench
To replace the faulty brake booster, follow these steps:
- Shut down the engine.
- Press the brake pedal until it becomes stiff to empty the vacuum line.
- Open the hood of the car.
- Disconnect the negative terminal of the battery from your car using the adjustable wrench. The negative terminal is usually covered with a black cap and will have a “-” label as shown in this image:
- Locate the brake booster near the wall of the engine compartment on the driver’s side of the car.
- Move the master cylinder to the side and then move on to step 8. If moving the master cylinder to the side is not possible in your vehicle model, then proceed to step 7.
- Remove the electric connector attached to the brake fluid reservoir by pulling it out by hand. You will need to push the tab of the connector to disconnect it.
- Use the ratchet with the appropriate socket to unscrew the mounting nuts of the master cylinder. To find the socket that fits on the mounting nuts, test with different sockets. If your master cylinder can be put aside, then jump to step 14.
- Ensure that the cap on the brake fluid reservoir is tightly secured to minimize fluid loss when disconnecting the brake lines.
- Use a brake line flare wrench to disconnect the brake lines as shown in this image:
- While pinching the brake lines remove the master cylinder from the vehicle.
- Put the master cylinder on a drip pan and let the brake fluid drain into the pan.
Warning: Brake Fluid is extremely corrosive and can damage painted surfaces. Wear gloves when handling brake fluid.
- Check the seal of the master cylinder. If there is a leak then brake fluid can seep into the brake booster and damage the vacuum seal of the brake booster. To determine if the seal of the master cylinder is damaged, follow this video:
To learn how to replace the seal of your master cylinder, follow this video:
- With the master cylinder out of the way, enter the cabin of your vehicle.
- Tilt your steering wheel up.
- Pull open the knee blocker underneath the steering wheel.
- Locate the push rod that is attached to your brake pedal.
- Detach the retaining clip that attaches the brake pedal to the push rod as shown here:
- Use the ratchet with an appropriate socket to unscrew the nuts that attach the brake booster to the wall of the engine compartment. You will find these nuts at the base of the push rod that you disconnected from the brake pedal in step 18.
- Disconnect the vacuum hose from the brake booster inside the engine compartment.
- Remove the brake booster from the engine compartment.
- Put back the new brake booster.
- Secure the booster to the wall of the engine compartment by screwing in the nuts through the open knee blocker.
- Reattach the brake pedal to the push rod of the new brake booster and put back the retaining clip.
- Replace the knee blocker panel.
- Remount the master cylinder to the brake booster.
- Reconnect the vacuum hose to the brake booster.
- If you had disconnected the brake lines, then reattach them using a brake line flare wrench. Then bleed the brake system and refill the brake fluid in the system.
If you do not know how to bleed the brakes of your car, follow this video:
- Reconnect the electrical wire to the brake fluid reservoir.
- Reconnect the negative terminal of the battery to the car using the adjustable wrench and put back the black plastic cap.
- Close the hood of the car.
Your brake booster has now been replaced.
Replacing A Faulty Brake Booster Vacuum Hose:
To replace the vacuum hose of your car, you will need these tools:
- A plier
- A new vacuum hose
- A clean cloth
Then follow these simple steps to replace the bad vacuum hose:
- Locate the vacuum hose. It is the pipe that connects your brake booster to the intake manifold of the engine.
- Using the plier, compress the two ends of the metal clips that hold the ends of the vacuum hose in place.
- Remove these metal clips:
- Pull and twist the ends of the hose until they come off.
- Clean the tube of the intake manifold and the brake booster to which the vacuum hose was secured.
- Connect one end of the new vacuum hose to the tube coming out of the brake booster.
- Connect the other end to the tube coming from the intake manifold of the engine:
- Clamp down the metal rings with the plier and pull them to either end of the vacuum hose.
Your vacuum hose is now replaced. Hopefully, your “Service Brake System” error has now been fixed.
Low Brake Fluid
If the level of brake fluid inside the brake fluid reservoir is low, that is the symptom behind this error.
Diagnosis
To check if the brake fluid level of your vehicle is low, follow these steps:
- Open the hood of your car.
- Locate the master cylinder of the brake system. It will be located on the driver’s side of the car near the back wall of the engine compartment. If you still can not find the master cylinder, consult the owner’s manual of your car. This is an image of the master cylinder that you are looking for:
- Check the level of brake fluid inside the reservoir of the master cylinder from the outside without opening the lid. The side of the reservoir will have markings to indicate the minimum level of brake fluid. If the brake fluid level is below this marking, that means you need to top up your brake fluid.
Solution
To add brake fluid to the brake fluid reservoir of the master cylinder, follow these steps:
- Park the vehicle on a flat surface: Ensure that the vehicle is parked on a level surface and the engine is turned off. For manual transmission vehicles, put the car in first gear and apply the parking brake.
- Locate the brake fluid reservoir: Open the hood and locate the brake fluid reservoir. There is usually a white or translucent container with a cap in the engine compartment near the driver’s side of the vehicle.
- Clean the reservoir cap: Clean the brake fluid reservoir cap if it’s dirty, so no debris falls into the reservoir.
- Choose the right brake fluid: Make sure to use the right brake fluid for your vehicle, as specified in the owner’s manual or on the reservoir cap.
- Open the reservoir cap: Unscrew the cap from the brake fluid reservoir by rotating it counterclockwise.
- Add brake fluid: Slowly pour the brake fluid into the reservoir until it reaches the “max” line on the outer wall of the reservoir. Be careful not to overfill the reservoir, as this can cause the fluid to spill out and damage the vehicle.
- Secure the reservoir cap: Securely screw the reservoir cap back on by rotating the cap in a clockwise direction.
- Test the brakes: After adding brake fluid, test the brakes by pumping them a few times to ensure that they are working properly.
- Dispose of old brake fluid: Dispose of the old brake fluid properly. Brake fluid is a hazardous material and should not be poured down the drain or thrown in the trash. Check with your local waste management facility for proper disposal methods. Alternatively, you can use kitty litter to dispose of brake fluid.
Contaminated Brake Fluid
Symptom
- Discolored brake fluid: When checking the brake fluid reservoir, you may notice its unusual color. While brake fluid can vary in hue, a darker tint, floating particles, or an emulsion may indicate contamination.
- Soft or spongy brake pedal: Contaminated brake fluid can cause the brake pedal to feel soft or spongy, making it harder to stop the vehicle. Water in the brake fluid can cause the brake lines to corrode and the brake fluid to become ineffective.
- Increased stopping distance: As brake fluid becomes dirtier, it will slowly lose its ability to slow your car down. If your car is taking longer to stop than normal, it may be a sign that the brake fluid needs to be replaced.
- Burning smell: When the brake fluid loses its hydraulic properties, it can create a burning smell when the brakes are applied.
- Noisy brakes: Contaminated brake fluid can cause brake system components to corrode and wear, leading to noisy brakes.
Solution
1. Prepare the car:
- Set the car in gear and place a stop behind the tires to keep it from rolling.
- Open the hood and locate the master cylinder.
- Open the master cylinder cap and place an old rag around it.
- Use a turkey baster to suck out most of the fluid. You may leave up to 20% of the old fluid in the cylinder.
- Refill the reservoir back up to the fill line using fresh brake fluid.
2. Bleed the brakes:
- Check the owner’s manual of your car to find out the order in which brake caliper to bleed first.
- Jack up the car and remove the wheel for the first caliper according to the order.
- Secure the car with jack stands.
- Locate the bleeder valve and attach a rubber hose to it.
- Have an assistant pump the brakes 4-5 times.
- While the assistant is holding the brake pedal down, open the bleeder valve and let fluid flow out.
- Close the bleeder valve when the brake pedal reaches the bottom.
- Repeat steps 5-8 for the remaining brake calipers.
3. Finish up:
- Top off the brake fluid in the reservoir to the max line.
- Torque the wheel bolts to proper specification.
- Verify that you have a solid brake pedal feel before driving.
Worn-Out Brake Pads
Symptoms
These are the symptoms that the “Service Brake System” error message is showing due to worn-out brake pads:
- Brakes Making High-Pitched Noises
- Loud, Grinding Noise When Braking
- Brake Pedal or Steering Wheel Shaking
- Increased Stopping Distance
- Visible Metal Backing on Brake Pads
Solution
Time required: The average time to change brake pads is about 1 hour.
Tools and materials required:
- Disposable mechanic’s gloves
- Jack and jack stands
- Lug wrench
- C-clamp or length of wood
- Wrench (socket, open end, or adjustable)
- Turkey baster
- Plastic tie, bungee cord, or piece of string
- New brake pads
- Can of brake fluid
Then follow these easy steps based on this picture of a disc brake system:
- Remove the wheel
- Park your car on a level surface.
- Engage the parking brake.
- Loosen the lug nuts on the wheel you want to work on.
- Jack up the car and place the jack stands under the frame.
- Lower the car onto the jack stands.
- Remove the lug nuts and take off the wheel.
- Remove the slider bolt
- Locate the slider bolts on the caliper.
- Use a wrench to loosen the slider bolts.
- Remove the slider bolts and set them aside.
- Pivot the caliper up
- The caliper should now be free to move.
- Carefully pivot the caliper up and away from the brake rotor.
- Slide out the old brake pads
- The old brake pads should now be visible.
- Use a pry bar to gently pry the old brake pads out of the caliper.
- Replace the retaining clips
- The new brake pads should come with new retaining clips.
- Use the old clips as a guide to install the new clips.
- Slide in the new brake pads
- Slide the new brake pads into the caliper.
- Make sure the pads are seated properly.
- Retract the pistons
- Use a C-clamp or a piece of wood to retract the pistons.
- Be careful not to damage the rubber boots or seals on the calipers.
- Monitor the brake fluid level
- As you retract the pistons, the brake fluid level will rise in the reservoir.
- Be sure to monitor the level and add more brake fluid if necessary.
- Reposition the caliper
- Carefully lower the caliper back into place.
- Make sure the caliper is seated properly.
- Reinstall the slider bolts
- Use a wrench to reinstall the slider bolts.
- Tighten the slider bolts to the specified torque.
- Repeat for the other side
- Repeat steps 1-10 for the other side of the car.
- Test-drive under safe conditions
- Once you have finished changing the brake pads, test-drive the car under safe conditions.
- Make sure the brakes are working properly.
A Bad Brake Pressure Sensor
Symptom
To determine if you have a bad brake pressure sensor connect an OBD 2 device to the OBD 2 port of your vehicle. Then check for the following error codes:
| Error Code | Meaning |
| 01435 | Brake pressure sensor 1 (G201) electrical fault in the circuit. |
| 5E20 | Pressure sensor 1 electrical fault |
| C1210 | Brake pressure sensor |
| C1288 | Brake pressure sensor circuit failure |
| 66-1 | Brake pressure sensor failure |
| C1288 | Pressure transducer main/primary input |
| C121D | Abnormality in brake fluid pressure sensor circuit |
| C1302 | Pressure sensor open circuit |
| 5124 | Pressure sensor circuit |
| C1028 | Master cylinder pressure sensor fault |
| C0131 | Pressure sensor circuit malfunction |
| 0130 | Brake pressure sensor signal missing |
| 0134 | Brake Pressure Sensor – Incorrect offset |
Solution
To replace the brake pressure switch sensor, follow this simple video:
Can I Drive With The Service Brake System Light On?
Yes, you can drive with the “Service Brake System” error message. But due to safety concerns, you should service the brake system as fast as possible. The message may disappear when driving. But it can show up again when you start your car or when you accelerate or press your brakes too hard. Moreover, the brake will feel firmer when the message shows up.
How Long Can I Drive With The Service Brake System Light On?
How long you can drive with the “Service Brake System” error message will depend on the cause of the error message. But you can still drive for some time with this error. If you get this message, get the issue fixed without delay.
How Do I Avoid The “Service Brake System” Error Message?
You can avoid the “Service Brake System” error message by following these maintenance processes regularly:
- Check Brake Pads and Rotors: Inspect the brake pads and rotors every 12,000 miles or as recommended in your vehicle’s manual. Look for wear and tear, uneven wear, and any damage. Listen for noises like grinding, growling, or squealing. If you notice any issues, replace the brake pads and rotors.
- Flush Your Brake Fluid: Replace your brake fluid every 2-3 years or as recommended in your vehicle’s manual. Brake fluid absorbs moisture over time, which can cause corrosion and damage to the brake system. Flushing the brake fluid removes any contaminants and moisture, ensuring that the brake system is functioning properly.
- Bleed the Brake Lines: Bleeding the brake lines removes any air bubbles that may have entered the brake system. This ensures that the brake system is functioning properly and that the brakes are responsive.
- Replace or Upgrade Brake Parts: Replace any worn or damaged brake parts, such as the master cylinder, brake lines, calipers, rotors, and pads. Consider upgrading to high-performance brake parts if you want better braking performance.
- Braking System Care: Take care of your braking system by keeping it clean and free of debris. Regularly inspect the brake hoses for cracks, blisters, or other signs of wear. Check the brake calipers and slide pin boots for damage. Ensure that the brake adjusters are properly set and that the clevis pins and anchor brackets are not worn.
By following these steps, you can ensure that your brake system is functioning properly and that your vehicle is safe to drive. Please refer to your vehicle’s manual for specific maintenance recommendations and seek professional assistance if you are unsure.
FAQs
Is it safe to drive with low brake fluid?
No, it is not safe to drive with low brake fluid. Brake fluid is an essential component of the braking system, and without adequate levels, the brakes will not work. It can cause a spongy brake pedal, decreased braking power, longer stopping distances, and even complete brake failure. If you notice low brake fluid levels, check for leaks first.
Why does my car shake when I brake at high speeds?
Your car shakes when braking at high speeds due to imbalance or dirty brake pads. An imbalanced or warped brake rotor may cause an abrupt jerk or intense vibration when braking. It is also possible to feel pulsations when applying the brakes if the brake pads are worn down or dirty.
Can tires cause vibration when braking?
Yes, tires can cause vibration when braking. But this happens only when your tires are worn out unevenly. Uneven tire wear can happen due to faulty wheel alignment. When braking an unevenly worn tire can wobble and vibrate.
Conclusion
So, now you know all there is to know about how to fix a Service Brake System.
It is important to quickly diagnose issues with your car’s brake system. I hope reading this article helped you easily determine the reason for this problem and apply the required fix.
