How Does Anti-Lock Braking Systems Work?

Because most of the cars on road in Ireland nowadays have an Antilock Braking Systems (ABS), I think we must take a look at how these work. This is surely going to clear up some of our myths about them. Different manufacturers have different versions of Antilock Braking Systems and because of this the specifications and name of the parts may also differ.

ABS is basically a four-wheel system, which prevents locking up of the wheel by modulating brake pressure automatically during emergency stop. When the wheels are prevented from being locked, it is the drivers who get a lot of benefit. It usually enables drivers to maintain steering control & to stop at once within a short distance.

If you are having a problem with ABS on your vehicle, always refer to the service & repair manuals for your vehicle. There are even many individuals or or car enthusiasts like me who in order to know more about ABS undergo practical courses ABS where they get a sound understanding of the modern antilock braking systems. There are in fact many such practical courses on automotive training services like courses on Launch X 431 training services, basic diagnostics, basic air conditioning etc. However, what I am going to describe here is how the ABS work.

ABS operate in the following ways:

• When brakes are used, a fluid is compelled from outlet ports to HCU inlet ports of the brake master cylinder. The pressure passes through 4 open solenoid valves inside HCU, then via outlet ports of HCY to every wheel.
• The main circuit of brake master cylinder basically feeds front brakes.
• Secondary circuit of brake master cylinder generally feeds rear brakes.
• When anti-lock brake control module becomes aware that the wheel is going to be locked, it closes open solenoid valve for circuit normally. This prevents further fluid from getting into the circuit.
• Anti-lock brake control component looks at anti-lock brake sensor signalling from affected wheel.
• If wheel decelerates even then, it opens solenoid valve for the circuit.
• After the wheel that was affected gets back the speed, anti-brake control unit returns solenoid valves to normal condition enabling flow of fluid to affected brake.
• Anti-lock brake control monitors electromechanical parts of system.
• Malfunctioning of ABS may cause the module of anti-lock brake control to check the system.
• A loss of the hydraulic fluid in brake master cylinder is going to make the anti-lock system disabled. Turning on the ignition switch to run position will enable the anti-lock brake control unit to perform a self-analysis on anti-lock electrical system, which will be indicated by 3 seconds illumination of yellow ABS warning indicator.
• When the vehicle is operating, the anti-lock brake control unit monitors all the electrical anti-lock functionalities & some of the hydraulic operations.
• When the car or truck is driven and it reaches a speed of about 20km/h, the module of anti-lock brake control basically turns on  the motor of the pump for ½ second. A mechanical sound can be heard during this time.
• When vehicle speed is below 20k/h, ABS will turn off.
• When the ABS & traction control system is going to malfunction, an ABS warning indicator yellow in colour is going to be illuminated.