Wabco 4757100390 Automatic Load Sensing Valve

Description

The Wabco 4757100390 Automatic Load Sensing Valve is a crucial component in air brake systems, designed to regulate braking force based on vehicle load. This valve is typically used in trucks, buses, and trailers to ensure optimal braking performance and stability. It automatically adjusts the air pressure to the brakes, preventing wheel lockup and maintaining directional control, particularly when the vehicle is heavily loaded. The valve features an actuation angle of -45° to +30°, a break point of 0.6 bar, and operates as a mechanical relay valve with a regulating ratio of 1:8. Its dimensions are 230 x 140 x 130 mm, and it includes connections with port threads of M22 x 1.5 and M16 x 1.5. This valve provides enhanced safety and efficiency by delivering consistent and reliable braking performance under varying load conditions, meeting OE specifications and operating within a temperature range of -40°C to +80°C.

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 4757100390) comes with a 1-year warranty.