GMC SAVANA 2013 Owner's Manual page 349

Wiper Blades
Wiper blades need to be cleaned
and kept in good condition to
provide a clear view.
Signs of wear include streaking,
skipping across the windshield,
and worn or split rubber.
Trained dealer technicians can
check the wiper blades and
replace them when needed.
Service and Maintenance 11-11