Symptom Chart - Brake System

WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

Condition	Possible Sources	Action
The red brake warning indicator and the yellow ABS warning indicator are illuminated	DTCs in the ABS module	REFER to VEHICLE DYNAMIC SYSTEMS article to diagnose the ABS module.
The red brake warning indicator is always/never on	Brake fluid level switch Parking brake switch Wiring, terminals or connectors Instrument cluster	REFER to INSTRUMENT CLUSTER (IC) AND WARNING CHIMES article to diagnose the red brake warning indicator.
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 .
	Brake discs	INSPECT the brake discs and the hubs for contamination or damage, INSTALL new as necessary.
	Brake calipers and/or guide pins	INSPECT the brake calipers and guide pins. REFER to Brake Calipers and Brake Caliper Guide Pins .
	Suspension component and/or wheel alignment	INSPECT the suspension and CHECK the wheel alignment. REFER to SUSPENSION SYSTEM - GENERAL INFORMATION article.
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	CARRY OUT the Brake Master Cylinder - Bypass Condition .
	Hydraulic control unit (HCU)	INSPECT the HCU. REFER to VEHICLE DYNAMIC SYSTEMS article.
The brake pedal eases down slowly	Air in the system	BLEED the system. REFER to Brake System Bleeding .
	Brake master cylinder	CARRY OUT the Brake Master Cylinder - Bypass Condition .
	HCU	INSPECT the HCU. REFER to VEHICLE DYNAMIC SYSTEMS article.
Brakes lock up under light brake pedal force	Brake pads	INSPECT the brake pads for uneven taper or excessive wear, REFER to Brake Pads .
	Brake calipers and/or guide pins	INSPECT the brake calipers and guide pins. REFER to Brake Calipers and Brake Caliper Guide Pins .
	Parking brake components	INSPECT the parking brake system. REPAIR or INSTALL new components as necessary. REFER to Parking Brake .
	Anti-lock brake control system	CHECK the anti-lock brake control system. REFER to VEHICLE DYNAMIC SYSTEMS article.
Excessive/erratic brake pedal travel	Brake fluid leaks and/or air in the system	INSPECT the system for leaks. REPAIR as necessary. BLEED the system. REFER to Brake System Bleeding .
	Brake calipers and/or guide pins	INSPECT the brake calipers and guide pins. REFER to Brake Calipers and Brake Caliper Guide Pins .
	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	CARRY OUT the Brake Master Cylinder - Bypass Condition and Brake Master Cylinder - Compensator Port .
	Brake pads	INSPECT the brake pads for taper wear. REFER to Brake Pads .
	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	CHECK the anti-lock brake control system. REFER to VEHICLE DYNAMIC SYSTEMS article.
Brakes drag	Parking brake component	INSPECT the parking brake system. REPAIR or INSTALL new components as necessary. REFER to PARKING BRAKE AND ACTUATION article.
	Brake caliper guide pins	INSPECT the caliper guide pins for correct operation. INSTALL new components as necessary. REFER to Brake Caliper Guide Pins .
	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 (vacuum boost)	CARRY OUT the Brake Booster - Vacuum Boost .
	Brake master cylinder	CARRY OUT the Brake Master Cylinder - Bypass Condition .
Brakes drag - all 4 wheels (vehicles equipped with Hydro-Boost®)	Return hose Hydro-Boost® brake booster	CHECK the Hydro-Boost® brake booster-to-power steering fluid reservoir return hose for kinks or restrictions. INSTALL a new hose as necessary. If the hose is OK, INSTALL a new Hydro-Boost® brake booster. REFER to POWER BRAKE ACTUATION article.
Brake pedal kickback - vehicles equipped with Hydro-Boost®	Incorrect power steering line installation at Hydro-Boost® brake booster	VERIFY that the power steering lines are correctly installed. REPAIR as necessary. REFER to POWER STEERING article.
	Power steering fluid contamination Hydro-Boost® brake booster	CARRY OUT the Power Steering System Filtering procedure in STEERING SYSTEM - GENERAL INFORMATION article.
Excessive brake pedal effort - vehicles equipped with vacuum boost	Brake booster vacuum hose	REROUTE, REPAIR or INSTALL new components as necessary.
	Brake booster check valve Brake booster source vacuum Brake booster	CARRY OUT the Brake Booster - Vacuum Boost .
Excessive brake pedal effort - vehicles equipped with Hydro-Boost®	Insufficient power steering pressure for brake booster operation Hydro-Boost® brake booster	CARRY OUT the Pump Flow and Pressure Test in STEERING SYSTEM - GENERAL INFORMATION article, Diagnosis and Testing.
	Leak in the hydraulic booster hoses or tubes	INSTALL new hoses or tubes as necessary.