Description: This bulletin describes the procedure to replace the brake
tubes for certain 2011MY
Sonata (YF) vehicles. The two brake lines connecting the brake system’s
master cylinder to the
Hydraulic Electronic Control Unit (HECU) may develop a leak over time due to
an insufficient seal
between the inner brake hose and metal brake line fitting.

Two symptoms can result from this condition. As the brake fluid leaks, there
may be a gradual
depletion of fluid in the brake fluid reservoir over time resulting in
complaints of a brake fluid leak. If
the leak continues unnoticed, the brake warning lamp in the instrument
cluster will illuminate.
Additionally, a fluid leak between the hose’s inner and outer layers may
restrict brake fluid flow
between the master cylinder and the circuit’s brake caliper(s). This may be
accompanied by
illumination of the Electronic Stability Control (ESC) warning lamp in the
instrument cluster.

If the brake tubes leak sufficient brake fluid, the brake warning lamp in
the instrument cluster will
illuminate and longer stopping distance will be required, increasing the
risk of a vehicle crash.

Applicable Vehicles: 2011 Sonata (YF) vehicles manufactured on December 11,
2009 through
September 1, 2010.

Posted in Service Campaign.