Do I need a brake proportioning valve?

A Proportioning valve is required on vehicles that have disc brakes on the front wheels and drum brakes on the rear wheels. Having the rear brakes engage first provides the control and stability needed to stop your vehicle safety. The proportioning valve reduces the pressure to the rear brakes.

What is a proportioning valve used for?

A proportioning valve is a valve that relies on the statics to supply a reduced pressure to an output line. A simple example is where spring load applies a reducing force so that the output pressure is reduced. Proportioning valves are frequently used in cars to reduce the brake fluid pressure to the rear brakes.

Are residual valves needed?

For this reason, residual pressure valves are not mandatory, however they can still be used. For instance, drum brake systems may result in a higher and firmer pedal feel when using a 10-psi residual valve compared to none at all.

When should a residual valve be used?

residual valve is used to hold pressure against the springs in the drum. This allows the drum brake to engage more quickly and reduces pedal travel. For an under-the-floor master cylinder brake system, a 2 lb. residual valve is used for disc brakes to keep brake fluid from flowing back down into the master cylinder.

Where should a residual pressure valve be installed?

This valve prevents fluid flow-back to the master cylinder reservoir which can cause excessive brake travel or “pumping” of the pedal to engage brakes. Install the valve as close as possible to the master cylinder and position the end marked “M.C.” toward the master cylinder and the end marked “OUT” toward the brakes.

How does a lever proportioning valve work on a car?

Lever Proportioning Valves Lever proportioning valves are also adjustable, but use a lever rather than a turn knob to adjust the rear brakes. These types of valves are typically ran in line with the rear brake lines. … Brake proportioning valves work exclusively with rear brakes.

When do you need an adjustable proportioning valve?

Adjustable proportioning valves are typically used in an aftermarket brake system where the vehicle owner might need to adjust the braking pressure going to the rear brakes. 3.

Can a brake proportioning valve be used on front brakes?

Brake proportioning valves work exclusively with rear brakes. They do no proportioning on front brakes. Most proportioning valves sold today also include a brake light switch. … Summit Racing tech adviser Mark Lake contributed to this report.

Do You need A proportioning valve for rear bias?

This is the only way that a proportioning valve can be effectively utilized. You should never assume that simply adding a proportioning valve will address all rear-bias conditions, as even the best proportioning valves must be well-matched to the target vehicle.

Where is the proportioning valve on a car?

For all street driven vehicles, the valve will be placed in the rear brake line to reduce the amount of fluid pressure supplied to the rear brakes. The amount of pressure reduction to the rear is adjustable by turning the knob on the proportioning valve.

When do you need a brake proportioning valve?

For these reasons, a brake proportioning valve is always required in automotive brake systems. These valves are sometimes referred to as a brake metering valve or a brake bias valve. If the valve has other features, like brake light pressure switch or an adjustable rear circuit these are often referred to as a combination valve.

What happens when a proportioning valve is failed?

On front to rear split hydraulic systems a failed proportioning valve should cause both rear wheels to lockup under panic braking – unless one rear brake has a condition that will prevent this (i.e. severely out of adjustment or seized wheel cylinder).