Hydraulic Brake System
WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, and 2003 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
Perform the Brake System Vehicle Road Test before performing SYMPTOM TESTS . See BRAKE SYSTEM VEHICLE ROAD TEST under SYSTEM TESTS. Review the system description and operation in order to familiarize yourself with the system functions. See DESCRIPTION & OPERATION .
Inspect for aftermarket devices which could affect the operation of the hydraulic brake system. See CHECKING AFTERMARKET ACCESSORIES . Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom. Inspect the brake fluid reservoir for the proper brake fluid level. Faulty electrical connections or wiring may be the cause of intermittent conditions.