Wabco 4757101220 Automatic Load Sensing Valve

Description

The Wabco 4757101220 Automatic Load Sensing Valve is a crucial component in air brake systems, designed to regulate braking force based on vehicle load. It's primarily used in commercial vehicles, trailers, and buses to ensure optimal braking performance and stability. This mechanical relay valve automatically adjusts the air pressure to the brakes, preventing wheel lockup and maintaining control even with varying loads. The valve measures 124 x 144 x 216 mm and features M22 x 1.5 and M16 x 1.5 port threads, along with a 4x M8 mounting configuration. Its technical specification adheres to OE standards, offering reliable performance across a temperature range of -40°C to +80°C. With a control stroke of 0° to +30°, a breakpoint of 0.7 bar and a regulating ratio of 01:08, this valve provides precise and consistent brake modulation for enhanced safety and efficiency.

Key Features & Benefits

This valve basically balances the air brake force between the tractor and trailer. It measures how much weight is being carried – how loaded up the trailer is – and adjusts the air pressure sent to the trailer brakes accordingly. It’s got an arm that moves with the suspension, sensing the change in load. It then proportionally increases or decreases the air signal. Think of it like a smart regulator, constantly adjusting to make sure you’ve got the right braking power for what you’re hauling. It’s a mechanical – pneumatic device, so it uses both physical movement and air pressure to do its job. It’s a key component in the air brake system, specifically designed for tractor – trailers. It connects to the trailer’s suspension and sends a signal back to the tractor’s brake system. This tells the tractor how much air pressure to apply to the trailer brakes. Without it, you’d either be under – braking a heavy load—dangerous—or over – braking an empty or lightly loaded trailer, which causes excessive wear and tear, and can even lock up the trailer wheels. It works with the spring brakes, too, making sure everything’s cooperating.

Symptoms, Risks & Replacements

It’s really important for safety and preventing damage. If it fails, you'll notice if the trailer brakes aren't applying evenly or are weak, or if they're locking up too easily. That can cause a pull to one side during braking, making it very difficult to control the vehicle. It protects your brakes, tires, and suspension from premature wear, too. It's a pretty crucial safety item. You can find these at places like Fixparts Online, and I’d recommend getting a quality one; it's not a place to cut corners. A failing valve can lead to some serious issues down the road.

Warranty Information

Wabco Automatic Load Sensing Valve (MPN 4757101220) comes with a 1-year warranty.