Wabco 4757155000 Load Sensing Emergency Valve

Description

The Wabco 4757155000 Load-Sensing Relay Emergency Valve is a critical component in air brake systems, designed to automatically apply the spring brakes when air pressure drops below a pre-set level. Primarily used in heavy-duty trucks and trailers, this valve ensures driver and vehicle safety by providing a fail-safe mechanism in case of air system failure. Its load-sensing functionality adjusts the emergency brake application based on vehicle load, preventing wheel lockup and maintaining directional stability. This valve features dimensions of 116 x 316 x 245 mm and includes multiple port connections: M16 x 1.5, M22 x 1.5, and M12 x 1.5, as well as a test connection. It operates pneumatically within a temperature range of -40°C to +80°C and is supplied as a device with an integrated emergency valve, conforming to OE specifications.

Key Features & Benefits

This valve basically monitors how much air pressure is needed for your brakes based on how loaded your vehicle is. It has two main jobs. First, it proportionally increases braking force as the load increases – so if you're hauling a full trailer, it applies the brakes harder than if you’re running empty. Second, it’s an emergency function – if there’s a major loss of air pressure in the system, it’ll kick in and apply the spring brakes, stopping the vehicle. It's kinda like a safety net built right into your air brake system. Think of it as the brain coordinating the braking effort with the weight you’re carrying. It reads signals from the suspension, figuring out if you've got a light load or a heavy one. That info is sent to the valve, which then adjusts the air pressure going to the brakes on the drive and trailer axles. Without it, your brakes wouldn’t be able to properly compensate for changes in weight, making stopping distances unpredictable and potentially dangerous. It's a crucial component of your air brake system, especially for commercial vehicles or anything that tows.

Symptoms, Risks & Replacements

It's important because it keeps you safe, plain and simple. If this valve fails, you could experience weak braking with a light load or overpowered brakes with a heavy one – neither is ideal. You’ll notice if it's going bad if your brakes feel different depending on how much you’re hauling, or if you get a warning light related to the air brake system. It acts like a shield, protecting you from brake failure due to load imbalance. A lot of folks get their parts from places like Fixparts Online, just to get a reliable one quickly, but the most important thing is making sure it's the correct part for your vehicle. A failing valve can lead to serious issues, so it’s something you definitely want to address right away.

Warranty Information

Wabco Load Sensing Emergency Valve (MPN 4757155000) comes with a 1-year warranty.