Water Hose Test

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Water Hose Test

Courtesy of GENERAL MOTORS CORP.

NOTE:

Use a water hose without the nozzle attached.

Have an assistant inside of the vehicle in order to locate the leak.
Begin testing at the base of the window or the windshield.
Slowly move the hose upward and across the top of the vehicle.