Symptom Charts

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. 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	REFER to ANTI-LOCK BRAKE SYSTEM (ABS) & STABILITY CONTROL to diagnose the ABS.
The red brake warning indicator is always/never on	Brake fluid level switch Parking brake switch Wiring, terminals or connectors Instrument Cluster (IC) Smart Junction Box (SJB)	REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES to diagnose the red brake warning indicator.
Vehicle pulls or drifts during braking	Tires	REFER to WHEELS AND TIRES to diagnose tire concerns.
	Brake calipers and/or guide pins Brake caliper anchor plate Brake flexible hose Brake pads Brake discs	INSPECT the brake system components. REFER to BRAKE SYSTEM INSPECTION .
	Suspension component(s) and/or wheel alignment	REFER to SUSPENSION SYSTEM - GENERAL INFORMATION to diagnose suspension system.
Brake pedal goes down fast or eases down slowly	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 master cylinder	CARRY OUT the BRAKE MASTER CYLINDER - BYPASS CONDITION .
	Hydraulic Control Unit (HCU)	REFER to ANTI-LOCK BRAKE SYSTEM (ABS) & STABILITY CONTROL to diagnose the HCU.
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. REFER to BRAKE SYSTEM INSPECTION .
Brakes lock up under light brake pedal force	ABS	REFER to ANTI-LOCK BRAKE SYSTEM (ABS) & STABILITY CONTROL to diagnose the ABS.
Excessive brake pedal travel (low/spongy pedal)	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 master cylinder	CARRY OUT the BRAKE MASTER CYLINDER - BYPASS CONDITION .
	Brake calipers and/or guide pins	INSPECT the brake calipers and guide pins. REFER to BRAKE SYSTEM INSPECTION .
	Brake flexible hose	INSPECT the brake flexible hoses during brake application. REFER to BRAKE SYSTEM INSPECTION .
	HCU	REFER to ANTI-LOCK BRAKE SYSTEM (ABS) & STABILITY CONTROL to diagnose the HCU.
Erratic brake pedal travel	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 .
	ABS	REFER to ANTI-LOCK BRAKE SYSTEM (ABS) & STABILITY CONTROL to diagnose the ABS.
	Hydro-Boost® brake booster	CARRY OUT the Power Steering System Filtering procedure in STEERING SYSTEM .
Brake drag	Stoplamp switch	VERIFY correct installation for the stoplamp switch. REFER to EXTERIOR LIGHTING .
	Parking brake component	REFER to PARKING BRAKE AND ACTUATION to diagnose the parking brake system.
	Brake caliper and/or guide pins	INSPECT the brake caliper and guide pins. REFER to BRAKE SYSTEM INSPECTION .
	Brake booster (vacuum boost) Brake master cylinder	CARRY OUT the BRAKE MASTER CYLINDER - COMPENSATOR PORT .
	HCU	REFER to ANTI-LOCK BRAKE SYSTEM (ABS) & STABILITY CONTROL to diagnose the HCU.
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 .
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 .
Brake pedal kickback - vehicles equipped with Hydro-Boost®	Power steering fluid contamination Hydro-Boost® brake booster	CARRY OUT the Power Steering System Filtering procedure in STEERING SYSTEM .
Excessive brake pedal effort - vehicles equipped with vacuum boost	Brake booster vacuum source Brake booster vacuum hose(s) Brake booster Brake booster check valve	CARRY OUT the BRAKE BOOSTER .
	Brake pads	INSPECT the brake pads. REFER to BRAKE SYSTEM INSPECTION .
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 .
Excessive brake pedal effort - vehicles equipped with vacuum boost (diesel only)	Brake booster vacuum source Brake booster vacuum hose(s) Brake booster Brake booster check valve Oil contamination of the brake booster assembly	NOTE: If oil contamination is found and the vacuum system is not replaced during brake booster replacement, booster failure will occur again. CARRY OUT the BRAKE BOOSTER . INSPECT the brake booster, vacuum lines and check valve for signs of oil, if oil is found in the vacuum line(s) or check valve, REPLACE the brake booster, all vacuum lines, vacuum reservoir and the vacuum pump at the same time.

NOTE: NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, refer to NOISE, VIBRATION & HARSHNESS . Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, refer back to NOISE, VIBRATION & HARSHNESS for the next likely system and continue diagnosis.

SYMPTOM CHART - NVH

Condition	Possible Sources	Action
Vibration when the brakes are applied	Brake disc(s) Suspension components	GO to PINPOINT TEST A .
Brake vibration/shudder - occurs when the brake pedal is released	Brake drag	GO to Symptom Chart - Brake System .
Rear brake noise - occurs when the brake pedal is unapplied	Parking brake component	REFER to PARKING BRAKE AND ACTUATION to diagnose the parking brake system.
Rattling noise	Caliper guide pins or guide pin bolts	CHECK the caliper guide pins and guide pin bolts. REFER to BRAKE SYSTEM INSPECTION .
	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.
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	INSPECT the brake pads. REFER to BRAKE SYSTEM INSPECTION .
Squealing noise - an intermittent squeal	Brake pads	Acceptable condition. Caused by cold, heat, water, mud or snow.
Groaning noise - occurs at low speeds with brake lightly applied (creeping)	Brake pads	Acceptable condition.
Grinding/moaning noise - continuous	Brake pads Brake disc	INSPECT the brake pads, brake discs and attaching hardware for damage. VERIFY brake components are within specifications. REFER to BRAKE SYSTEM INSPECTION .