Brakes are pretty much the most important safety device on your truck or RV. If you’ve ever partially lost your brakes in the past, you’ll agree that it’s not something you want to experience again. Inspecting your brakes twice a year for wear and damage can protect you and your passengers. Additionally, it will also help save you money by catching any damage before it becomes too costly.
Brake System Components That Can Fail
The master cylinder, the heart of the trucks braking system, holds the brake fluid when it is not being delivered to the brakes through the brake lines. If brake fluid leaks because the master cylinder is worn or brake lines are plugged or broken, the fluid cannot be delivered and the brake pads will become ruined.
The brake fluid itself can become dirty or contaminated as it draws rust-causing moisture and picks up other debris, or it can break down from excess heat. Clean brake fluid is either clear or slightly yellow, while dirty brake fluid may be brown or even black. Old and dirty brake fluid can damage ABS brake systems internally.
The brake lines connect to the master cylinder through a combination valve, which combines a metering and proportioning valve. It regulates the pressure on the front and rear wheels to make sure both sets of brakes are applied simultaneously. A malfunctioning combination valve may cause the wheels to lock up.
Brake pads and shoes can be made of ceramic, metal or organic materials, while the disc rotors and drums they press against are made of metal. Because the pads and shoes create friction to stop the truck, they gradually wear down over time and may wear away completely, letting the metal of the calipers and cylinders they are attached to grind against the rotors and drums and damage them. (Some pads have a metal strip attached that sounds a warning whistle when the pad becomes too worn, but this strip sounds only when the truck is in motion and the brakes are not applied.
It is important to understand the key components to a Vehicle equipped with an Air Brake System. When the Brake pedal is applied The Brake Valve gives air to various check valves and relay valves that apply air to each slack adjuster, the slack adjuster then rotates the “S” Cam to press the shoe up against the brake drum. When the pedal is released the air pressure is taken away, which puts the shoes and drums back into a “free” position. It is important that we inspect the Air Lines, Valves, Slack Adjusters, as well as the condition of the Shoes and Drums. The inspection of the Air Brake system is a big part of our standard 20 Point Inspection.