Tools You'll Need:
* Brake bleeding kit: This usually includes a clear hose, a wrench that fits your bleeder valve, and a container to catch the fluid. You can also improvise this using a length of clear tubing, a wrench, and a jar.
* New brake fluid: Use the type specified for your vehicle (DOT 3, DOT 4, DOT 5.1 – never mix types). Brake fluid is corrosive, so wear appropriate eye protection and gloves.
* Wrench: The correct size to fit your bleeder valve.
* Helper: It's much easier to have someone pump the brake pedal while you bleed the system.
* Clean rags or paper towels: To clean up spills.
* Torque wrench (optional but recommended): To tighten bleeder valves to the manufacturer's specifications after bleeding.
Steps:
1. Safety First: Wear safety glasses and gloves. Work in a well-ventilated area. Brake fluid is corrosive and harmful to skin and eyes.
2. Locate Bleeder Valves: These are usually located on the brake calipers (at each wheel). They are small valves with a square or hexagonal head.
3. Prepare the System: Ensure the brake fluid reservoir is topped off with fresh fluid. Check the level regularly during bleeding, as you'll be removing fluid from the system.
4. Attach the Bleeding Kit: Attach one end of the clear hose to the bleeder valve and the other end to the container to collect the old fluid.
5. Bleeding Procedure (with a helper):
* Have your helper slowly and steadily pump the brake pedal several times.
* While the pedal is depressed, open the bleeder valve slightly using your wrench. You should see brake fluid flowing through the hose; it should initially be dark and possibly contain air bubbles.
* Close the bleeder valve before your helper releases the brake pedal.
* Repeat this process several times until you no longer see air bubbles in the fluid.
6. Repeat for Each Wheel: Bleed each wheel in a specific order. The order typically starts with the furthest wheel from the master cylinder and works its way closer. Refer to your vehicle's repair manual for the correct bleeding order. Common sequences include: Rear passenger, rear driver, front passenger, front driver. *Improper order can lead to air trapped in the system*
7. Check Brake Fluid Level: Continuously monitor and top off the brake fluid reservoir as needed during bleeding. Low fluid levels can introduce air back into the system.
8. Final Check: Once all wheels are bled, have your helper pump the brake pedal firmly several times. The pedal should feel firm and responsive. If it feels soft or spongy, you might need to repeat the bleeding process.
9. Tighten Bleeder Valves: Once you're finished, tighten the bleeder valves securely using your wrench. If you have a torque wrench, use it to tighten to the manufacturer's specifications to prevent leaks.
10. Test Drive: After bleeding the brakes, perform a test drive to verify they are working correctly. Start with a low-speed test in a safe, open area before driving normally.
Troubleshooting:
* Air Bubbles Still Present: You might have a leak in the system, a damaged master cylinder, or a faulty caliper. Inspect your brake lines and components thoroughly.
* Spongy Pedal After Bleeding: This could indicate insufficient bleeding, air in the system, or a faulty master cylinder or other component.
* Brake Fluid Leak: Identify and repair the leak before driving.
Important Note: If you're uncomfortable performing this procedure yourself, take your vehicle to a qualified mechanic. Improper bleeding can lead to brake failure, which can be dangerous. Always consult your vehicle's repair manual for specific instructions and bleeding order.
