A failing ABS will cause the brake pedal to go to the floor when there is internal damage in the system, such as damage to the ABS pump.
Failure of the pump will cause the brake system to lose hydraulic pressure, sinking the brake pedal.
However, it is important to note that ABS failure is not the only cause of this problem.
This article will examine the principle governing the ABS, symptoms of failures, and further discuss some related questions you may have.
ABS System Working Principle
The Anti-brake system is a safety feature designed to prevent one or more wheels from locking up, especially during sudden activation of the emergency handbrake.
When the wheel is locked, it stops rotating, causing the car to slide. Previously, drivers tried to tackle this issue by pumping the brakes to gain control.
Now, the advanced ABS technology has made it easier for the driver. He can now focus on steering the car to safety while the abs unlock the wheel.
In addition, the ABS relies on data collected by many car sensors, such as the wheel speed sensor and others, to monitor the wheel condition of the car. All of this data allows it to properly and accurately adjust traction.
Concerning a sinking pedal, the ABS pumps contain valves operated by solenoids, which the module uses to restore hydraulic pressure to the brakes.
When the ABS module detects a slip in any of the wheels, a signal is sent to the pump. The valve then releases hydraulic pressure to the brakes. In this situation, the system can pump the brakes up to 15 times per second.
Internal damage in the ABS pump will cause the brake system to lose hydraulic pressure. It could also cause hydraulic fluid to leak, leading to a sinking brake pedal.
Symptoms of Bad ABS System
When your ABS is going bad, the first sign is the ABS warning. Other signs include various malfunctions with the brake system.
The following are the signs that the ABS is faulty.
Brakes lock up
The primary responsibility of an ABS is to prevent the wheel from locking up during heavy braking. However, the system will malfunction when the ABS module fails and may experience more wheel lock during heavy braking. As the ABS module begins to fail, it becomes less reliable.
Unresponsive brake pedal
Another sign of a failing ABS is a less effective or slow response when hitting the brakes. Sometimes, the brake is applied multiple times before getting a response or, worse, no response.
A failing ABS module can affect your speedometer. It could influence the speedometer to show the wrong speed. In some cases, the speedometer will be at 0mph.
Increase effort in pressing the brake pedal.
Brake pedals are easy to press under normal working conditions and require minimal effort when the ABS works correctly. Although, the stiff brake pedal may be traced to causes other than failing abs.
A triggered ABS warning light is the apparent symptom of a failing ABS. Usually, the ABS warning light comes on for a few seconds before going off when the engine is ignited. However, when it remains on, the ABS has developed an issue.
You can switch off the engine and turn it on to reset the ABS module. However, for serious faults, the warning will still appear. If the light goes off, the ABS module may have been confused by some transient issues.
Common Problems with ABS System
Below are some of the common abs problems:
- Damaged sensors which feed the ABS module with inaccurate data.
- Bad master cylinder or ABS module.
- Faulty ABS pump
- Wiring problem
- Low or contaminated brake fluid.
Can ABS Cause Brake Pedal to Go to the Floor?
When the brake pedal goes to the floor sometimes, it can be traced to a damaged ABS pump. The pump controls hydraulic pressure that activates the brakes. When damaged, the hydraulic pressure drops instantly.
A problem like “brake pedal goes to floor but fluid is full” shows that hydraulic pressure in the brake system is low. A leak in the brake system is a significant cause of sinking brake pedals.
In addition, internal damage to components in the ABS, like the pump valve, can cause hydraulic fluid to leak, causing a spongy feeling in the brake pedal.
What is Brake Pedal Resistance?
Brake pedal resistance refers to how hard or firm the pedal feels when pressuring the pedal. The resistance you feel on the brake relies on various brake components. When the brake pedal resistance is too much, it could mean that the brake fluid is leaking or contaminated.
How to Fix Sinking Brake Pedal?
If you have a sinking brake pedal, it could be caused by many factors, including brake fluid leak, falter ABS pump, brake pad wear, and faulty ABS module. You will need a proper diagnosis or test components to determine where the problem originated.
Below is how you can fix a sinking pedal.
Test and fix the ABS pump
Using a scan tool, you can test the condition of the ABS pump. Connect the tool to your vehicle’s OBD II port. In addition, run an output test for the pump motor.
Also, inspect the fuse box for blown fuse and have it changed immediately. We recommend changing the pump motor or pressure switch if the fuse is OK.
Test and fix the ABS module
Check if the ABS module works fine using the diagnostic scan tool. Scan the vehicle for any error related to the ABS module. It could be either a software issue or the module is entirely damaged.
It is best to have a professional fix this problem because it may require much mechanical knowledge.
Find and fix leaks.
Brake leaks are easy to find; look under the hood and check where the fluid leaks. You can trace it up to where exactly in the car the leak is. Once the leak is found, try fixing the leak.
The ABS comprises many components that could affect the braking system. It is why you should consider getting professional help when having a problem when applying ABS. A professional will guarantee an accurate job and prevent further damage to any other component.