GM Service Manual Online
For 1990-2009 cars only

Caution: Refer to Safety Glasses Caution in the Preface section.

Caution: Refer to Vehicle Lifting Caution in the Preface section.

Caution: Refer to Brake Dust Caution in the Preface section.

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.

  1. In order to inspect for external brake fluid leaks, first inspect the fluid level in the master cylinder.
  2. 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.

  3. If the fluid level is abnormally low, adjust the brake fluid level. Refer to Master Cylinder Reservoir Filling.
  4. Start the engine and allow it to idle.
  5. Apply constant, moderate foot pressure to the brake pedal.
  6. If the brake pedal gradually falls away while under foot pressure, there may be a brake fluid leak.

  7. Turn the ignition OFF .
  8. Visually inspect the following brake system components for brake fluid leaks, greater than desired corrosion, and damage. Give particular attention to all brake pipe and flexible hose connections to make sure that there are not any slight brake fluid leaks [dash ] even though the brake pedal may feel firm and hold steady:
  9. • Master cylinder brake pipe fittings.
    • All brake pipe connections.
    • Brake pipes.
    • Brake hoses and connections.
    • Brake calipers.
  10. 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, inspect the hydraulic brake system to make sure of correct function.