According the National Highway Traffic Safety Administration (NHTSA), based on a notice from Kia, rear brake calipers that might not have been properly machined. The affected vehicles were made between September 14, 2010 and October 4, 2010.
The issue could cause brake fluid to leak, and could lead to a soft or spongy pedal feel. The brake warning light would also signal the issue which, if ignored could lead to "reduced braking power and increased risk of a crash."
Owners of the affected Sorento models—who will be notified of the effort beginning this month—should bring their vehicle back to the dealership, where rear calipers will be inspected and replaced if necessary.
If Sorento owners have any questions, they should contact their dealership or Kia's Customer Assistance Center at 800-333-4542, or they may call NHTSA's safety hotline at 888-327-4236.