Wabco 4757020027 Automatic Load Sensing Valve

Description

The Wabco 4757020027 Automatic Load Sensing Valve is a critical component within air brake systems, primarily used in commercial vehicles to regulate braking force based on vehicle load. It ensures optimal braking performance and stability by automatically adjusting the air pressure delivered to the service brakes, preventing wheel lockup and maintaining control. This valve features a mechanical, dynamic type of operation with an actuation angle of -40° to +28°, a regulating ratio of 1:7, and operates at a maximum pressure of 10.0 bar within a temperature range of -40°C to +80°C. The dimensions of the valve are 162 x 156 x 176 mm, and it utilizes M22 x 1.5 threads for both ports, with mounting via 4x M8 bolts and a bolt spacing of 84x84 mm. It is an exchange unit for 475 702 002 0 and meets OE specification for reliable performance.

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 4757020027) comes with a 1-year warranty.