Brake System External Leak Inspection
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.
NOTE:
Prior to performing any work, review warnings, cautions and notes. See ADJUSTMENTS & INSPECTIONS WARNINGS, CAUTIONS & NOTES under SERVICE PRECAUTIONS.
- In order to inspect for external brake fluid leaks, first check the fluid level in the master cylinder. While a slight brake fluid level drop can be considered a normal condition due to brake lining wear, a very low level may indicate a brake fluid leak in the hydraulic system.
- If the fluid level is abnormally low, adjust the brake fluid level. See MASTER CYLINDER RESERVOIR FILLING under BLEEDING BRAKE SYSTEM.
- Start the engine and allow it to idle.
- Apply constant, moderate foot pressure to the brake pedal. If the brake pedal gradually falls away while under foot pressure, there may be a brake fluid leak.
- Turn OFF the ignition.
- Visually inspect the following brake system components for brake fluid leaks, excessive corrosion, and damage. Give particular attention to all brake pipe and flexible hose connections to ensure that there are not any slight brake fluid leaks, even though the brake pedal may feel firm and hold steady.
- Master cylinder brake pipe fittings.
- All brake pipe connections.
- Brake pipes.
- Brake hoses and connections.
- Brake calipers and/or wheel cylinders (if equipped).
- While slight dampness around the master cylinder reservoir can be considered acceptable, brake fluid leaking from any of the brake system components requires immediate attention. If any of these components exhibit signs of brake fluid leakage, repair or replace those components. After the repair or replacement, reinspect the hydraulic brake system to assure proper function.