Why do rear brakes apply before disc brakes?
This is done because the shoes in a drum brake system must travel farther and require more fluid movement to activate than is required in a disc brake. Having the rear brakes apply first provides stability during braking and helps keep the car traveling in a straight line.
How are rear brakes related to body lift?
The amount of body weight shift and rear body lift is directly proportional to vehicle weight and load. The proportioning valve applies more pressure to the rear brakes to counteract body lift. The valve is often attached mechanically to the vehicle body by a rod.
What kind of valve does rear drum brake use?
In some vehicles, car makers may install up to three valves/switches or one “combination switch.” Metering valve: Allows brake fluid flow to rear drum brakes before providing pressure to the disc brakes.
How does the proportioning valve on the rear brake work?
The proportioning valve applies more pressure to the rear brakes to counteract body lift. The valve is often attached mechanically to the vehicle body by a rod. As the rear body lifts, the rod moves a piston in the proportioning valve to apply more pressure and reduce the lift.
When do I need to change my rear brakes?
Determining Problems One of the keys to knowing when you should change the rear brakes on your vehicle is to determine if they are wearing out. Usually, the front brakes need to be replaced before the rear brakes, but there are exceptions to any situation. There is no set mileage to change rear brakes.
Do you need to do a complete brake job?
Many technicians recommend rebuilding or replacing calipers and wheel cylinders as part of a complete brake job — and with good reason. Over time, rubber seals on caliper and wheel cylinder pistons harden and lose elasticity.
What’s the difference between front and rear brakes?
One of the major issues with selling customers a “complete” brake job is that the components in the brake system do not wear at the same rate. The front brakes typically wear two to three times faster than the rear brakes.
Why do I need to adjust my brake pad?
Modern braking systems typically are self-adjusting to ensure that the brake pad maintains constant contact with the braking surface on a rotor or drum when the brakes are applied. Older brakes may need periodic adjustment where the pad is realigned to close the gap between it and the surface by tightening adjustment screws in the brake mechanism.