Symptom Chart: Brake System
WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostics in this information assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods .
| Condition | Possible Sources | Actions |
|---|---|---|
| The red brake warning indicator and the yellow ABS warning indicator are illuminated | Diagnostic Trouble Codes (DTCs) in the ABS | CHECK for ABS diagnostic trouble codes (DTCs). REFER to: Anti-Lock Brake System (ABS) and Stability Control . |
| The red brake warning indicator is always/never on | Brake fluid level switch Parking brake switch Wiring, terminals or connectors IPC BCM |
REFER to: Instrumentation, Message Center and Warning Chimes . |
| Vehicle pulls or drifts during braking | Brake calipers and/or guide pins Brake flexible hose Brake pads Brake discs |
INSPECT the brake system components. INSTALL new components as necessary. |
| Tires | REFER to: Wheels and Tires . | |
| Suspension component(s) and/or wheel alignment | REFER to: Suspension System . | |
| Brake pedal goes down fast or eases down slowly | Brake fluid leaks and/or air in the system | INSPECT the system for visible signs of brake fluid leakage. REPAIR as necessary. BLEED the system. REFER to: Brake System Pressure Bleeding . If no visible signs of leakage are found, INSPECT for brake master cylinder fluid leakage into the brake booster. If there is evidence of fluid in the brake booster, INSTALL a new brake master cylinder and brake booster. REFER to: Brake Master Cylinder . REFER to: Brake Booster . Also, for vehicles equipped with an EcoBoost engine, INSPECT for evidence of brake fluid in the vacuum tube. If there is evidence of brake fluid in the vacuum tube, INSTALL a new vacuum tube and brake vacuum pump. REFER to: Brake Vacuum Pump - 2.7L EcoBoost (238kW/324PS) . REFER to: Brake Vacuum Pump - 3.0L Power Stroke Diesel . |
| Brake master cylinder | CARRY OUT Component Test- Brake Master Cylinder - Bypass Condition | |
| HCU | REFER to: Anti-Lock Brake System (ABS) and Stability Control . | |
| Brake pedal | INSPECT the brake pedal and bracket assembly. INSTALL a new brake pedal and bracket as necessary. REFER to: Brake Pedal and Bracket . | |
| Brakes lock up under light brake pedal force | Brake pads Brake flexible hose Brake disc Brake calipers and/or guide pins |
INSPECT the brake system components. INSTALL new components as necessary. |
| ABS | REFER to: Anti-Lock Brake System (ABS) and Stability Control . | |
| Excessive brake pedal travel (low/spongy pedal) | Brake fluid leaks and/or air in the system | INSPECT the system for visible signs of brake fluid leakage. REPAIR as necessary. BLEED the system. REFER to: Brake System Pressure Bleeding . If no visible signs of leakage are found, INSPECT for brake master cylinder fluid leakage into the brake booster. If there is evidence of fluid in the brake booster, INSTALL a new brake master cylinder and brake booster. REFER to: Brake Master Cylinder . REFER to: Brake Booster . Also, for vehicles equipped with an EcoBoost engine, INSPECT for evidence of brake fluid in the vacuum tube. If there is evidence of brake fluid in the vacuum tube, INSTALL a new vacuum tube and brake vacuum pump. REFER to: Brake Vacuum Pump - 2.7L EcoBoost (238kW/324PS) . REFER to: Brake Vacuum Pump - 3.0L Power Stroke Diesel . |
| Brake master cylinder | CARRY OUT Component Test- Brake Master Cylinder - Bypass Condition . | |
| Brake calipers and/or guide pins | INSPECT the brake calipers and guide pins. INSTALL new components as necessary. | |
| Brake flexible hose | INSPECT the brake flexible hoses during brake application. INSTALL a new brake hose as necessary. REFER to: Front Brake Flexible Hose . REFER to: Rear Brake Inner Flexible Hose . REFER to: Rear Brake Outer Flexible Hose . | |
| Erratic brake pedal travel | Brake pedal | INSPECT the brake pedal for binding, obstructions and correct interface to booster rod. REPAIR as necessary. CHECK the brake pedal fasteners for correct torque. REFER to: Brake Pedal and Bracket . |
| ABS | REFER to: Anti-Lock Brake System (ABS) and Stability Control . | |
| Brake drag | Parking brake component | INSPECT the parking brake system. INSTALL new components as necessary. |
| Brake caliper and/or guide pins Brake flexible hose Brake booster |
INSPECT the brake system components. INSTALL new components as necessary. | |
| Brake master cylinder | CARRY OUT Component Test- Brake Master Cylinder - Compensator Port . | |
| Hydraulic Control Unit (HCU) | REFER to: Anti-Lock Brake System (ABS) and Stability Control . | |
| Stoplamp switch | VERIFY correct installation of the stoplamp switch. REFER to: Stoplamp Switch . | |
| Excessive brake pedal effort | Vacuum on demand system fault | Using a diagnostic scan tool, CARRY OUT the PCM self-test. DIAGNOSE all PCM Diagnostic Trouble Codes (DTCs). REFER to: Electronic Engine Controls . |
| Insufficient vacuum for brake booster operation Brake booster manifold vacuum hose Brake booster Brake booster check valve Brake booster vacuum pump |
CARRY OUT Component Test- Brake Booster | |
| Brake pads | INSPECT the brake pads. INSTALL new components as necessary. REFER to: Front Brake Pads . REFER to: Rear Brake Pads . |