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Brake System Inspection and Test

Inspect the brake system components listed. Repair or replace any parts that are leaking or damaged.

Component Inspections:

Also check for
Master Cylinder
Look for damage or signs of fluid leakage at:
  • Reservoir tank, subreservoir or master cylinder body.
  • Lines, reservoir tank hose and grommets, and their joints.
  • Between master cylinder and booster.
Bulging seal at reservoir cap. This is a sign of fluid contamination.
Brake Hoses
Look for damage or signs of fluid leakage at:
  • Line joints and banjo bolt connections.
  • Hoses and lines, also inspect for twisting or damage.
Bulging, twisted, or bent lines.
Look for damage or signs of fluid leakage at:
  • Piston seal.
  • Banjo bolt connections.
  • Bleed screw.
Seized or sticking caliper pins.
ABS Modulator-control Unit
Look for damage or signs of fluid leakage at:
  • Line joints.
  • Modulator-control unit.

Brake System Test
Brake pedal sinks/fades when braking
  1. Set the parking brake, and start the engine, then turn off the A/C. Allow the engine to warm up to normal operating temperature (radiator fan comes on twice).
  1. Attach a 50 mm (2 in.) piece of masking tape along the bottom of the steering wheel, and draw a horizontal reference mark across it.
  1. With the transmission in neutral (M/T) or P or N (A/T), press and hold the brake pedal lightly (about the same pressure needed to keep an A/T-equipped vehicle from creeping), then release the parking brake.
  1. While still holding the brake pedal, hook the end of the tape measure behind the brake pedal, then pull the tape up to the steering wheel. Note the measurement between the brake pedal and the reference mark on the steering wheel.
  1. Apply steady pressure to the brake pedal for 3 minutes.
  1. Watch the tape measure.
    • If the measurement increases 10 mm (0.39 in.) or less, the master cylinder is OK.
    • If the measurement increases more than 10 mm (0.39 in.), replace the master cylinder.