The Using to Truck Relay Valve

A truck relay valve is used to control the brakes in a heavy truck. This device is located near the rear axles. When the driver presses the brake pedal, the relay valve opens and the air is directed to the rear service brake chambers. The resulting pressure is then matched by the control pressure coming from the foot-valve. In a split second, the brakes are applied.

The main function of a relay valve is to reduce the time it takes to apply the brakes on a heavy truck. This shortens the braking reaction time and also shortens the time it takes for the pressure to settle in the system.

Relays are typically used to correct the lag between the front and rear brakes of long wheelbase vehicles. They provide a fast response and help reduce the lag by providing compressed air from the air reservoir to the brake chamber. Air is then forced into the brakes immediately upon activation of the valve.

Relays are used in air braking systems as well as in parking brake systems. Typically, a relay valve has two or more outputs and is installed at the end of a long brake line. These valves are connected to a brake chamber, an air reservoir, or both. Some models are also designed to be operated by the steering wheels.

In a dual-circuit air brake system, the primary and secondary reservoirs of a tractor are connected to a relay valve, which is located at the end of the brake line. The relay valve receives the air from both reservoirs and merges it through a two-way check valve. If the tractor's braking circuit fails, the control pressure from the foot-valve still controls the trailer service brakes through the relay valve.

The air in the reservoir is supplied to the relay valve through a pipe. After the merged air passes through the two-way check valve, it is redirected through the vehicle's air tank. The air is then sent out to the rear wheels. As with any braking system, the dependability of a relay valve depends on the condition of its lines and parts.

For example, a large diameter pipe connects the primary reservoir to the relay valve. All valves are equipped with mounting holes. To replace a valve, you may need to install a separate mounting bracket. You can find a replacement part by looking for the manufacturer's part number stamped on the valve.

A truck relay valve is a common piece of equipment on heavy trucks. Because it is an air-operated device, it allows air to be delivered to the vehicle's rear wheels without the need for a large volume of air to travel. It is an important part of the truck's braking system, and can prevent the vehicle from grinding to a stop in an unsafe area.