Replacing brake fluid involves draining the old fluid and then performing a process of flushing and bleeding the system to introduce new fluid and remove air.
Step-by-Step Guide to Replacing Brake Fluid
Based on the provided reference, the process of replacing brake fluid can be broken down into several key steps:
Preparation: Draining the Old Fluid
The first step is to address the fluid currently in the system.
- 1) Drain the old fluid: Locate the brake master cylinder, which is usually under the hood of your vehicle. Remove its cap and drain off as much of the old fluid as possible. This removes the majority of the degraded fluid before you introduce the new.
The Replacement and Bleeding Process
After removing the bulk of the old fluid from the reservoir, the following steps are performed to replace the fluid throughout the brake lines and components. The reference groups the remaining actions as 2) Change brake fluid, followed by the specifics:
- 3) Flush the calipers/wheel cylinders: This involves pushing the new fluid through the brake lines to expel the old fluid and any contaminants from the calipers or wheel cylinders located at each wheel.
- 4) Bleed the brakes: This is a critical part of the process. Bleeding removes any air bubbles that may have entered the system during the fluid change. Air in the brake lines can lead to a spongy pedal feel and significantly reduced braking performance.
- 5) Top-up: As you flush and bleed the system, the fluid level in the master cylinder reservoir will drop. You must top-up the reservoir with new, clean brake fluid as needed to prevent air from being drawn into the system.
- 6) Repeat the process: The flushing and bleeding steps (3-5) must be repeated for each brake line and caliper/wheel cylinder in the vehicle. It's common practice to start with the wheel furthest from the master cylinder and work your way to the closest one. This ensures that the system is thoroughly flushed and bled.
By following these steps – draining the initial fluid from the reservoir, and then flushing, bleeding, and topping up at each wheel, repeating the process as necessary – you can effectively replace the brake fluid in your vehicle's hydraulic braking system.
