Hyundai Sonata LF: General Information / Troubleshooting

Hyundai Sonata LF 2014-2019 Service Manual / Brake System / General Information / Troubleshooting

Troubleshooting

Problem Symptoms Table

Use the table below to help you find the cause of the problem. The numbers indicate the priority of the like cause of the problem. Check each part in order.

If necessary, replace these parts.

Symptom	Suspect Area	Reference
Lower pedal or spongy pedal	1. Brake system (Fluid leaks) 2. Brake system (Air in) 3. Piston seals (Worn or damaged) 4. Rear brake shoe clearance(Out of adjustment) 5. Master cylinder (Inoperative)	repair air·bleed replace adjust replace
Brake drag	1. Brake pedal free play (Minimum) 2. Parking brake lever travel (Out of adjustment) 3. Parking brake wire (Sticking) 4. Rear brake shoe clearance(Out of adjustment) 5. Pad or lining (Cracked or distorted) 6. Piston (Stuck) 7. Piston (Frozen) 8. Anchor or shoe (Inoperative) 9. Booster system (Vacuum leaks) 10. Master cylinder (Inoperative)	adjust adjust repair adjust replace replace replace replace repair replace
Brake pull	1. Piston (Sticking) 2. Pad or lining (Oily) 3. Piston (Frozen) 4. Disc (Scored) 5. Pad or lining (Cracked or distorted)	replace replace replace replace replace
Hard pedal but brake inefficient	1. Brake system (Fluid leaks) 2. Brake system (Air in) 3. Pad or lining (Worn) 4. Pad or lining (Cracked or distorted) 5. Rear brake shoe clearance(Out of adjustment) 6. Pad or lining (Oily) 7. Pad or lining (Glazed) 8. Disc (Scored) 9. Booster system (Vacuum leaks)	repair air·bleed replace replace adjust adjust replace replace repair
Noise from brake	1. Pad or lining (Cracked or distorted) 2. Installation bolt (Loosen) 3. Disc (Scored) 4. Sliding pin (Worn) 5. Pad or lining (Dirty) 6. Pad or lining (Glazed) 7. Anchor or shoe (Faulty) 8. Brake pad shim (Damage) 9. Shoe hold-down spring (Damage)	replace adjust replace replace clean replace replace replace replace
Brake fades	1. Master cylinder (Inoperative)	replace
Brake vibration, pulsation	1. Brake booster (Vacuum leaks) 2. Pedal free play 3. Master cylinder (Inoperative) 4. Caliper (Damage) 5. Master cylinder cap seal 6. Damaged brake lines	replace adjust replace replace replace replace
Brake Chatter	Brake chatter is usually caused by loose or worn components, or glazed or burnt linings. Rotors with hard spots can also contribute to brake chatter. Additional causes of chatter are out-of-tolerance rotors, brake lining not securely attached to the shoes, loose wheel bearings and contaminated brake lining.

Special Service Tools

Special Service Tools Tool(Number and Name)IllustrationUse09581-11000Piston expanderSpreading the rear disc brake piston.09580 - 0U000Brake piston adjusterRemoval and installation of the rear disc brake piston...

Brake System

Other information:

Hyundai Sonata LF 2014-2019 Service Manual: Input shaft speed sensor 2 Description and Operation

Description • Components location : DCT (Dual Clutch Transmission) • Function The input shaft speed sensor is important in that it detects the input shaft RPM and sends this information to the Transmission Control Module (TCM). It provides important input information for electric control...

Hyundai Sonata LF 2014-2019 Service Manual: TPMS Sensor Description and Operation