how to fix Volvo XC90 brake warning light on dashboard

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, brake fluid, and a vacuum pump.
• Ensure the vehicle is parked on a level surface and the engine is off. Engage the parking brake.

2. Check and Refill Brake Fluid

• Locate the brake fluid reservoir under the hood.
• Remove the cap and check the fluid level against the minimum and maximum indicators.
• If low, use the appropriate type of brake fluid (DOT 4 for most Volvo models) to fill to the correct level.
• Replace the cap securely.

3. Inspect and Replace Brake Pads and Rotors (if necessary)

• Raise the vehicle using a jack and secure it with jack stands.
• Remove the wheels to access the brake components.
• Inspect brake pads for thickness; replace if less than 3mm.
• Check rotors for scoring or warping; replace if necessary.
• Remove the caliper using a socket set, and replace pads and rotors as needed, applying anti-squeal lubricant to the back of pads.
• Torque the caliper bolts to manufacturer specifications (typically around 25-35 ft-lbs).

4. Check Brake Lines and Components

• Inspect brake lines for any signs of damage or leaks.
• Replace any damaged lines or fittings using new parts.
• Ensure all connections are tight and secure.

5. Test Brake Booster

• Start the engine and press the brake pedal several times; it should feel firm.
• If the pedal sinks to the floor, check for vacuum leaks or a faulty brake booster.
• Replace the brake booster if necessary, ensuring all connections are properly fitted.

6. Reconnect and Reset Warning Light

• After repairs, reconnect the battery if it was disconnected.
• Use the OBD-II scanner to clear any fault codes and reset the brake warning light.
• Test drive the vehicle to ensure proper braking function.