Vehicles on the road today have a much more complex and sophisticated system than in yesteryear. Cars today generally have a four wheel hydraulic braking system, to exert pressure on all four wheels, allowing the car to stop in a straight and even line.
What occurs when you put on the “brakes” The pressure that you apply to the pedal is transmitted to the brake system master cylinder (either directly or through a booster assembly by means of hydraulic brake fluid to the wheel cylinders fundamentally through a series of steel lines and flexible hoses.
As the pressure is supplied to the wheel cylinders, it causes the cylinder pistons to move and pressure is applied to the brake drum or discs through the brake shoes or pads. The friction that then exists between the brake shoes or pads (which are lined with friction materials) and the brake drum or disc is what stops the wheels from turning round. Hence your wheels will stop rotating and your vehicle should slow down and come to a stop.
What topics should be on such a list for the technician, mechanic or service writer to check off? First the brake pedal and master cylinders must be checked. Check the brake pedal “free play”. There should be ample travel; the pedal should be firm and not spongy. The master cylinder should not be leaking and the fluid levels of the braking hydraulic fluids should be adequate or topped up. Next check the stoplight switch. Check switch operation by inspecting rear brake lights when brake pedal is applied. A helper of set of mirrors can be of assistance. Wheel cylinders and brake shoe assemblies require periodic inspections. Of course brake drums must be checked for out or round or tapered conditions. Along with that and thorough visual inspection of seals, brake lines and hoses must be completed. In the case of disc brakes brake pads should be checked for wear. Along with that check the rotors or discs for scoring, cracking, uneven wear or warping. Lastly caliper pistons should show no signs of leakage at all.
On some luxury premium vehicles four way disc type brakes are offered either as a standard safety or as an option. Along with that brake and braking systems have become much more sophisticated with time. A good majority of cars now sold are equipped with ABS anti-lock braking systems. Actually rather simple in electronics, ABS systems allow for the vehicle not to stop in a shorter distance but allow the motorist to be able to steer away from danger in emergency driving situations.