The brake system of a vehicle is made up of a hydraulic system, which supplies hydraulic fluid pressure from the master cylinder, through brake lines and hoses, to the wheel cylinder and calipers.
The wheel cylinder and calipers are responsible for applying fluid pressure to the frictional parts of the system, thereby causing the vehicle to decelerate to a stop.
Most vehicles weigh over 2 tons and every time brakes are applied, it takes a lot of friction to bring that much weight to a stop. So, a certain amount of wear and tear is expected in the brake lining and brake pads (or shoes), which could lead to brake failure if not checked.
A certain woman (names withheld), recounting her experience with brake failure, could hardly remember any other thing except for the terror she felt after stepping on the brake pedal and realizing that the car neither slowed down nor stopped.
She was lucky enough to have been driving with someone else in the car, who quickly pulled the emergency brake, and guided the steering, until the car pulled to a stop.
Note that the failed brake could have been as result of a number of preventable reasons, bearing in mind that brakes don’t just fail all of a sudden. They always give warning signals.
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So, in order to effectively guard against brake failure, it’s important for you to learn how to pay attention to these warning signals.
Brake warning light
Your vehicle has a warning light on your dashboard, which is automatically turned on when there is an issue in your brake system. The warning may not necessarily be alarming; it could only be a reminder that your emergency brake (parking brake) has not been released.
On the other hand, if the light stays on persistently after releasing the emergency brake, it means there’s something more serious going on. In this case, you need to check for fluid or air leakages either in your brake hose, brake lines, brake caliper, wheel cylinder, or in your master cylinder.
Squeaking or squealing sound
A squeaking or squealing sound is an indication that your brake pad or shoe is wearing thin. If nothing is done about it in time, it eats into the rotors, which produce a vibrating or grinding sound each time the brake is applied. The smart thing to do is to change the pads before it gets to the rotors, as this will save you cost.
Weak or hard brake pedal
An effective brake pedal should be firm when it is stepped on, not weak or hard to push down; either of these conditions is an indication of air in the brake line. Brake line air prevents hydraulic fluid from travelling, as it should. It reduces the hydraulic pressure of the system and consequently causes a loss in braking power. To resolve this, you may simply unscrew the brake bleeder valve and remove air by a process called bleeding the air.
A weak brake pedal could also be as a result of shortage of brake fluid due to leakage from a damaged or corroded brake line, brake caliper, wheel cylinder or even a worn-out master cylinder.
Replace the affected part as soon as possible and always top up the brake fluid after every three months.
This is caused by excessive heat. A very hard metallic spot is formed on the brake drums or rotors, which consequently affects friction. The implication is that the brake pads or shoes will be unable to hold unto the rotor when the brake is applied.
You need a professional to shave out the hard spot so that the rotors can become smooth again to enable adequate friction with the brake pads or shoes.
Does your vehicle keep pulling to one side each time the brake is applied? It probably needs wheel alignment. You could also check if your brake lining is wrongly positioned and re-adjust it. If the brake pads or shoes unevenly wearing thin caused the pulling, replace them to avoid further complications.