How to replace brake fluid

Replacing brake fluid is a safety-critical job. If done incorrectly, it can leave air in the braking system and reduce braking performance. Take your time, or consider a professional if you’re unsure.

What you’ll need

• Correct brake fluid type (e.g., DOT 3, DOT 4, or DOT 5.1 — check owner’s manual)

• Jack and axle stands (or ramps)

• Wheel nut wrench

• Clear tubing + container (for bleeding)

• Spanner for bleed nipples (often 8–11 mm)

• Brake fluid bleeder kit (optional but helpful)

• Gloves and eye protection

• Clean rags

Step 1: Safety first

• Park on level ground.

• Engage handbrake and select Park/gear.

• Ensure the engine is off.

• Brake fluid damages paint—cover nearby surfaces.

Step 2: Locate the brake fluid reservoir

• Open the bonnet.

• Find the translucent reservoir near the rear of the engine bay.

• Clean around the cap before opening it.

• Fill to the MAX line with fresh brake fluid if needed.

Step 3: Understand bleeding order

You usually bleed brakes in this order (check manual as it may vary):

• Rear right

• Rear left

• Front right

• Front left

(Some vehicles differ depending on ABS layout.)

Step 4: Raise the car (if needed)

• Lift the vehicle safely using a jack.

• Secure with axle stands.

• Remove wheels for easier access to bleed nipples.

Step 5: Bleeding each brake

For each wheel:

1. Attach clear tube to bleed nipple.

2. Place the other end in a container with a little brake fluid (prevents air re-entry).

3. Have a helper press the brake pedal slowly.

Then:

• Open bleed nipple slightly → fluid/air comes out

• Close nipple before pedal is released

• Repeat until fluid runs clear and bubble-free

Keep an eye on the reservoir:

• Do not let it run dry or air will enter the system.

Step 6: Repeat for all wheels

• Move in the correct sequence.

• Top up reservoir regularly during the process.

Step 7: Final top-up

• Fill reservoir to the MAX line once all bleeding is complete.

• Secure the cap tightly.

Step 8: Test the brake pedal

• With engine off, press brake pedal:

  • It should feel firm, not spongy.

• Start engine:

  • Pedal may drop slightly but should remain firm.

Step 9: Check for leaks and clean up

• Inspect all bleed nipples and connections.

• Wipe away any spilled brake fluid immediately.

• Refit wheels and torque wheel nuts properly.

Tips

• Brake fluid absorbs moisture over time and should typically be replaced every 2 years.

• Use only the specified DOT rating—mixing types can damage the system.

• If pedal feels soft after bleeding, air is still present and the process must be repeated.

Safety notes

• Brake failure risk is real if this is done incorrectly.

• Never drive the car if the brake pedal feels spongy or inconsistent.

• If ABS systems behave oddly after a flush, some vehicles may require diagnostic bleeding using a scan tool.