Symptom Chart

WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM CHART

Condition	Possible Sources	Action
The red brake warning indicator is always on	Brake fluid level	FILL the brake fluid reservoir to the MAX line.
	Electronic parking brake (EPB)	CHECK that the parking brake system is fully released.
	Circuitry	GO to PINPOINT TEST A .
	Instrument cluster	GO to PINPOINT TEST A .
The red brake warning indicator is inoperative	Circuitry Bulb	REFER to INSTRUMENT CLUSTER .
The brakes pull or drift	Tire air pressure	CHECK the tires for uneven or excessive wear and correct inflation.
	Brake pads	CHECK the brake pads for uneven taper or excessive wear. REPAIR as necessary.
	Brake components	CHECK the brake discs and the hubs for damage. REPAIR as necessary.
	Suspension component	CHECK the wheel alignment. REFER to SUSPENSION SYSTEM-GENERAL INFORMATION .
	Wheel alignment
The brake pedal goes down fast	Brake fluid level	INSPECT the system for leaks. FILL the brake master cylinder reservoir. BLEED the system. REFER to BRAKE SYSTEM BLEEDING in this article .
	Air in the system	INSPECT the system for leaks. BLEED the system. REFER to BRAKE SYSTEM BLEEDING in this article .
	Brake master cylinder	CARRY OUT the Brake Master Cylinder Component Test in this article .
The brake pedal eases down slowly	Air in the system	INSPECT the system for leaks. BLEED the system. REFER to BRAKE SYSTEM BLEEDING in this article .
The brake pedal eases down slowly	Brake master cylinder	CARRY OUT the Brake Master Cylinder Component Test in this article .
The brakes lock up under light brake pedal force	Brake pads	CHECK the brake pads for uneven taper or excessive wear. REPAIR as necessary.
	Brake component	CHECK the brake components for correct operation. REPAIR as necessary.
	Parking brake component	REPAIR or INSTALL new components as necessary. REFER to PARKING BRAKE & ACTUATION .
	Anti-lock brake control system	CHECK the anti-lock brake control system. REFER to ANTI-LOCK CONTROL .
Excessive/erratic brake pedal travel	Leak in the hydraulic system Air in the system Disc brake caliper	INSPECT the system for leaks. BLEED the system. REFER to BRAKE SYSTEM BLEEDING in this article .
	Brake master cylinder	CARRY OUT the Brake Master Cylinder Component Test in this article .
	Brake pads	CHECK the brake pads for excessive wear.
	Brake pedal	CHECK the brake pedal for binding or obstructions. REPAIR as necessary.
The brakes drag	Parking brake component	REPAIR or INSTALL new components as necessary. REFER to PARKING BRAKE & ACTUATION .
	Brake caliper guide pins	REPAIR or INSTALL new caliper guide pins, seals, and boots. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
	Brake caliper	REPAIR or INSTALL new brake calipers as necessary. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
	Brake booster	CARRY OUT the Brake Booster Component Test in this article .
	Brake master cylinder	CARRY OUT the Brake Master Cylinder Component Test in this article .
Excessive brake pedal effort	Brake booster	CARRY OUT the Brake Booster Component Test in this article .
	Brake booster check valve	CARRY OUT the Check Valve Component Test in this article .
	Brake booster manifold vacuum hose	REROUTE, REPAIR, or INSTALL new components as necessary.
The adjustable pedal does not operate correctly	Adjustable pedal motor Circuitry Adjustable pedal motor cables Manual switch	GO to PINPOINT TEST C .
The adjustable pedal does not operate correctly	Front electronic module (FEM) module	REFER to the FRONT ELECTRONIC MODULE (FEM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
Rattling noise	Caliper mounting bolts loose	CHECK the caliper bolts. TIGHTEN to specification. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
	Damaged or worn caliper guide pins or retainers	CHECK the caliper guide pins and retainers for lubrication and correct operation. LUBRICATE or INSTALL new components as necessary. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
	Missing or damaged anti-rattle clips or springs	CHECK the brake pads for missing clips or broken springs. INSTALL new components as necessary. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
	Loose brake disc shield	TIGHTEN the brake disc shield bolts to specification. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
Clicking noise - with the brakes applied with anti-lock brake system (ABS) brakes	ABS hydraulic control unit (HCU)	Acceptable condition.
Squealing noise - occurs on first (morning) brake application	Brake pads	Acceptable condition. Caused by humidity and low brake pad temperature.
Squealing noise - a continuous squeal	Brake pads or linings worn below the minimum thickness	INSPECT brake pads for excessive wear, taper wear, or uneven wear. VERIFY brake pads are within minimum the specification. REFER to BRAKE PADS in this article .
Squealing noise - an intermittent squeal brought on by cold, heat, water, mud, or snow	Brake pad	Acceptable condition.
Groaning noise - occurs at low speeds with brake lightly applied (creeping)	Brake pads	Acceptable condition.
Grinding noise - continuous	Brake pads or linings worn below the minimum thickness	INSPECT the brake pads, brake discs, and attaching hardware for damage. VERIFY the brake pads are within minimum the specification. REFER to BRAKE PADS in this article .
Moaning noise	Brake linings contaminated with grease or oil	INSPECT the brake pads for contamination. REPAIR or INSTALL new components as necessary. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
NOTE: The driver door module (DDM) controls the vehicle memory system. The front electronic module (FEM) sends and receives memory information to/from the DDM through the standard corporate protocol (SCP) communication network. If a system fault cannot be corrected in this article , refer to MODULE COMMUNICATIONS NETWORK for further diagnosis. The adjustable pedal memory function does not operate - manual switch commands functional	Circuit(s) Adjustable pedal potentiometer FEM	GO to PINPOINT TEST D .
Vibration when the brakes are applied	Uneven brake pad wear Brake disc pad transfer Brake disc	COMPLETE the brake system inspection. REFER to INSPECTION AND VERIFICATION in this article .
Vibration when the brakes are applied	Suspension components	GO to PINPOINT TEST E .
Brake vibration/shudder - occurs when the brake pedal is released	Brake caliper guide pins	INSPECT the brake caliper guide pins for correct operation. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.
	Brake drag	INSPECT the brake pads for premature wear. REPAIR or INSTALL a new caliper as necessary. REFER to FRONT DISC BRAKE for front disc brakes or REAR DISC BRAKE for rear disc brakes.