Brake & Front End October, 1943: Inspecting drum brakes was very labor intensive. Pulling the wheel was typically the only way to see the shoes.
The parking or emergency brake has to perform two distinct jobs. First, it must be able to hold the vehicle on an incline. Second, it must be able to stop a vehicle under a specific distance if the hydraulic brakes have failed. These standards are set by the Department of Transportation (DOT), and the kicker is these standards must be met with the force applied by a little old lady. But, over time, the cables can stretch and the friction materials change their length and thickness, which is why adjustments to the system are required.
Caliper replacement may be necessary in high-mileage vehicles because of fluid leaks or because the calipers are sticking.
With these vehicles, the major aggravation for shops is brake noise and uneven brake pad wear.
When you think about the braking system of a vehicle, you probably think about the major parts you see when removing the wheel: brake pads, rotors, calipers and maybe hydraulics. However, one of the most important parts of the system isn’t visible: brake fluid. Brake fluid comes in several formulations for different applications and plays
Worn brake pads can tell you a lot about the entire brake system and keep new components from suffering the same fate.
Passive types of wheel speed sensors are still used in many applications so understanding their operation is important.