Symptom Chart - Brake System

2009 Ford Fusion SEL, 3.0 1, FWDSECTION Symptom Chart - Brake System
WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Symptom Chart - Brake System

Condition Possible Sources Action
  • The red brake warning indicator and the yellow ABS warning indicator are illuminated
  • DTCs in the ABS module
  • The red brake warning indicator is always/never on
  • Brake fluid level and/or brake fluid leaks
  • Parking brake
  • Wiring, terminals or connectors
  • High-speed controller area network (HS-CAN) bus
  • Instrument cluster
  • The brakes pull or drift
  • Tires
  • INSPECT the tires for uneven or excessive wear, and correct inflation. REFER to WHEELS AND TIRES article.
 
  • Brake pads
  • INSPECT the brake pads for contamination, uneven taper or excessive wear. REFER to Brake Pads in this service information.
 
  • Brake discs
 
  • Brake calipers and/or guide pins
  • INSPECT the brake calipers and guide pins. REFER to Brake Calipers and Brake Caliper Guide Pins in this service information.
 
  • Suspension component and/or wheel alignment
  • Brake pedal goes down fast
  • Brake fluid leaks and/or air in the system
  • INSPECT the system for leaks. REPAIR as necessary. FILL the brake master cylinder reservoir. BLEED the system. REFER to Brake System Bleeding .
 
  • Brake master cylinder
  • Preform the Brake Master Cylinder Component Test in this service information.
 
  • Hydraulic control unit (HCU)
  • The brake pedal eases down slowly
  • Air in the system
 
  • Brake master cylinder
  • Preform the Brake Master Cylinder Component Test in this service information.
 
  • HCU
  • Brakes lock up under light brake pedal force
  • Brake pads
  • INSPECT the brake pads for uneven taper or excessive wear. REFER to Brake Pads in this service information.
 
  • Brake calipers and/or guide pins
  • INSPECT the brake calipers and guide pins. REFER to Brake Calipers and Brake Caliper Guide Pins in this service information.
 
  • Anti-lock brake control system
  • Excessive/erratic brake pedal travel
  • Brake fluid leaks and/or air in the system
 
  • Brake calipers and/or guide pins
  • INSPECT the brake calipers and guide pins. REFER to Brake Calipers and Brake Caliper Guide Pins in this service information.
 
  • Brake flexible hose
  • INSPECT the brake flexible hoses for swelling and damage. INSTALL new as necessary. REFER to FRONT DISC BRAKE article for front disc brakes or REAR DISC BRAKE article for rear disc brakes.
 
  • Brake master cylinder
  • Preform the Brake Master Cylinder Component Test in this service information.
 
  • Brake pads
  • INSPECT the brake pads for taper wear. REFER to Brake Pads in this service information.
 
  • Brake pedal
  • INSPECT the brake pedal for binding, obstructions and correct installation. REPAIR as necessary. CHECK the brake pedal fasteners for correct torque. REFER to Specifications in HYDRAULIC BRAKE ACTUATION article.
 
  • Anti-lock brake control system
  • Brakes drag
  • Parking brake component
 
  • Brake caliper guide pins
  • INSPECT the caliper guide pins for correct operation. INSTALL new components as necessary. REFER to Brake Caliper Guide Pins in this service information.
 
  • Disc brake caliper(s)
  • REPAIR or INSTALL new brake calipers as necessary. REFER to FRONT DISC BRAKE article for front disc brakes or REAR DISC BRAKE article for rear disc brakes.
 
  • Brake booster
  • Preform the Brake Booster Component Test in this service information.
 
  • Brake master cylinder
  • Preform the Brake Master Cylinder Component Test in this service information.
  • Excessive brake pedal effort
  • Insufficient engine vacuum for brake booster operation
 
  • Brake booster manifold vacuum hose
  • VERIFY engine vacuum at the booster. REROUTE, REPAIR or INSTALL new components as necessary.
 
  • Brake booster
  • VERIFY engine vacuum at the booster. Preform the Brake Booster Component Test in this service information.
 
  • Brake booster check valve
  • VERIFY engine vacuum at the booster. Preform the Check Valve Component Test in this service information.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.