Audi Brake Hydraulic Line Front Left (RS4) - Genuine Audi 4B3615133D

Product Information

A brake hydraulic line is a high-pressure tube or hose in a vehicle’s braking system that carries brake fluid from the master cylinder to the brake calipers or wheel cylinders. It’s a critical part of a hydraulic braking system, where brake fluid pressure is used to apply the brakes.

Hydraulic lines can be made of steel tubing (hard lines) or reinforced flexible rubber/stainless braided hoses (flex lines, usually near the wheels to allow movement).

• Spongy or Soft Brake Pedal: Air or fluid leaks in the line reduce pressure, making the pedal feel soft or sink lower than normal.
• Reduced Braking Power / Increased Stopping Distance: A leak lowers fluid pressure, so brakes won’t engage as strongly.
• Brake Fluid Leaks: Visible puddles or drips under the car, usually near a wheel or along the undercarriage. Brake fluid is typically clear to light brown and slippery.

About Genuine Audi

The original parts used by Audi to build your car are available as replacement parts under the “Genuine Audi” brand. Manufactured under the direction of Audi, expect excellent quality and a premium price since these parts are available exclusively through the Audi Dealership network.

You may not realize this, but the parts that make up your Audi are not necessarily manufactured by Audi. No cause for concern, as Audi designs the part, hires a manufacturer, and ensures its quality to you. In fact, many of these manufacturers have been making parts for Audi for decades. In our industry these manufacturers are called OEM (Original Equipment Manufacturers), and these are often brands you recognize, including Lemforder, ZF, Sachs, Bosch, Valeo, Zimmermann, Siemens VDO, Corteco, and more. Don’t be surprised to open that Genuine Audi parts box and find an OEM branded part inside, simply with the addition of an Audi logo.

Be sure to keep an eye out for OE tags on our product pages to quickly identify parts coming direct from OE manufacturers. That extra bit of insight could save you some serious money while shopping! Refer to our OE Academy for further information regarding the OE/OEM tags throughout the site.