How does a proportioning valve equalize braking action?
The proportioning valve reduces the pressure to the rear brakes. If equal braking force were applied to all four wheels during a stop, the rear wheels would lock-up before the front wheels. The proportioning valve only lets a portion of the amount of pressure to the rear wheels thus preventing rear wheel lock-up.
Do I need a adjustable proportioning valve?
High performance brake systems such as those equipped with 4-piston or 6-piston calipers, we always suggest an adjustable proportioning valve. The adjustable valve will allow the driver to increase or decrease the amount of rear braking force so that it can be matched to the front.
What does a combination valve do?
Most combination valves perform 3 functions: The Proportioning Valve keeps the rear brakes from locking up during a panic stop. The Metering Valve delays the front brakes long enough for the fluid pressure to overcome the rear brake return springs. A pressure switch sends an electrical signal.
What does a load sensing proportioning valve do?
load sensing proportioning valve (SABS), essentially, SABS only one hydraulic mechanical means; load sensing valve role is to ensure the proper ratio of front and rear wheels during running load and ensure emergency braking when the vehicle is not a rear wheel locking.
Why a height sensing proportioning valve is used on some vehicles?
Height sensing proportioning valves are connected to the hydraulic lines leading to the rear drums located between the vehicle’s chassis and the rear axle. When a panic braking situation occurs, the rear end of the vehicle lifts up and forward, increasing the chance of rear wheel lock-up.
When would you use a proportioning valve?
The proportioning valve typically connects the master cylinder to the rest of the braking system, but sometimes it is independent of the cylinder. This valve is necessary for optimizing front-to-rear bias, also referred to as brake balance.