2021-2024 Kia Sorento and Sportage Front Brake Judder TSB

Kia has issued Technical Service Bulletin (TSB) CHA126V to address instances of front brake judder experienced by owners of certain 2021-2024 Kia Sorento (MQ4a) and 2023-2024 Kia Sportage (NQ5a) vehicles. This condition manifests as a vibration or pulsing sensation during braking, which can be felt in the steering wheel, brake pedal, or even the seat.

The TSB provides a detailed procedure for technicians to inspect the vehicle and, if necessary, replace the front brake discs and associated parts to resolve the Kia Sorento brake judder issue.

Symptoms

Owners may notice the following symptoms indicating front brake judder:

• A vibration sensation during braking.
• A pulsing sensation felt through the brake pedal.
• Vibration in the steering wheel when the brakes are applied.
• A general pulsing sensation felt in the seat while braking.

Important Warnings for Owners

Kia has provided several important advisories regarding this TSB:

• "A Technical Service Bulletin is a field fix repair program without customer notification that may be performed during the warranty period." This means owners will not receive a direct notification letter for this issue.
• "This bulletin should only be performed with valid customer complaint of front brake judder." Technicians will only proceed with the inspection and repair if the customer reports the specific symptom.
• "Brake Pads are not eligible for replacement under this TSB." The TSB specifically covers brake discs and caliper guide bolts, not brake pads.
• "Caliper carrier guide mounting bolts are not reusable. Install new parts." This highlights the necessity of using new bolts during the repair.
• "Once the repair is performed and the brake rotors are replaced, TSB CHA126V is complete. Any subsequent or follow-up concerns must be addressed according to normal Service/Warranty Guidelines." This clarifies that the TSB covers a specific repair, and any further issues fall under standard warranty procedures.
• "Brake linings, including pads and shoes, and clutch linings are warranted for 12 months/12,000 miles, whichever comes first, if they fail to function properly during normal use."

Diagnosis Procedure

To diagnose the front brake judder, technicians are instructed to perform a specific test drive:

1. Safely test drive the vehicle, accelerating to 50 mph where speed limits allow and traffic is minimal. A straight, long, open road is recommended.
2. Apply the brake pedal with moderate force (approximately 0.3g deceleration rate) to slow the vehicle from 50 mph down to 10 mph. This braking action should take about 6 seconds.
3. Repeat the braking instructions from step 1 for a total of ten (10) times, allowing for minimal cooling time between repetitions. Technicians will monitor brake performance throughout this process.
4. After the test, the technician will determine if brake judder (steering wheel/front vehicle vibration or pulsing) was present during braking.
   • If judder was present (NG), the technician will proceed with the replacement procedure.
   • If no judder was present (OK), no action is required, and an inspection Op Code will be claimed.

Repair Procedure Summary

If front brake judder is confirmed, the repair involves replacing both front brake discs. The general steps include:

1. Referring to the