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Brake System Service

AUT 114

Brake System Service

AUT 114

Course Description

Prerequisite: Minimum C (2.0) grade in both AUT 100 and AUT 108. Studies drum, disc, hydraulic, power assist, antilock terminology, operation, and diagnosis. Develops skills on drum, disc, hydraulic, power assist, and antilock brake systems. (40-60)

Outcomes and Objectives

Diagnose general brake systems. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Identify and interpret brake system concern; determine necessary action. P-1
  • Research applicable vehicle and service information, such as brake system operation, vehicle service history, service precautions, and technical service bulletins. P-1
  • Locate and interpret vehicle and major component identification numbers (VIN, vehicle certification labels, calibration decals). P-1

Diagnose and repair hydraulic system. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose pressure concerns in the brake system using hydraulic principles (Paschal’s Law). P-1
  • Measure brake pedal height; determine necessary action. P-2
  • Check master cylinder for internal and external leaks and proper operation; determine necessary action. P-2
  • Remove, bench bleed, and reinstall master cylinder. P-1
  • Diagnose poor stopping, pulling or dragging concerns caused by malfunctions in the hydraulic system; determine necessary action. P-1
  • Inspect brake lines, flexible hoses, and fittings for leaks, dents, kinks, rust, cracks, bulging or wear; tighten loose fittings and supports; determine necessary action. P-2
  • Fabricate and/or install brake lines (double flare and ISO types); replace hoses, fittings, and supports as needed. P-2
  • Select, handle, store, and fill brake fluids to proper level. P-2
  • Inspect, test, and/or replace metering (hold-off), proportioning (balance), pressure differential, and combination valves. P-2
  • Inspect, test, and adjust height (load) sensing proportioning valve. P-3
  • Inspect, test, and/or replace components of brake warning light system. P-3
  • Bleed (manual, pressure, vacuum or surge) brake system. P-1
  • Flush hydraulic system. P-3

Diagnose and repair drum brake systems. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose poor stopping, noise, pulling, grabbing, dragging or pedal pulsation concerns; determine necessary action. P-1
  • Remove, clean (using proper safety procedures), inspect, and measure brake drums; determine necessary action. P-1
  • Refinish brake drum. P-1
  • Remove, clean, and inspect brake shoes, springs, pins, clips, levers, adjusters/self-adjusters, other related brake hardware, and backing support plates; lubricate and reassemble. P-1
  • Remove, inspect, and install wheel cylinders. P-2
  • Pre-adjust brake shoes and parking brake before installing brake drums or drum/hub assemblies and wheel bearings. P-1
  • Install wheel, torque lug nuts, and make final checks and adjustments. P-1

Diagnose and repair disc brake systems. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose poor stopping, noise, pulling, grabbing, dragging or pedal pulsation concerns; determine necessary action. P-1
  • Remove caliper assembly from mountings; clean and inspect for leaks and damage to caliper housing; determine necessary action. P-1
  • Clean and inspect caliper mounting and slides for wear and damage; determine necessary action. P-1
  • Remove, clean, and inspect pads and retaining hardware; determine necessary action. P-1
  • Disassemble and clean caliper assembly; inspect parts for wear, rust, scoring, and damage; replace seal, boot, and damaged or worn parts. P-2
  • Reassemble, lubricate, and reinstall caliper, pads, and related hardware; seat pads, and inspect for leaks P-1
  • Clean, inspect, and measure rotor with a dial indicator and a micrometer; follow manufacturer’s recommendations in determining need to machine or replace. P-1
  • Remove and reinstall rotor. P-1
  • Refinish rotor according to manufacturer’s recommendations. P-1
  • Adjust calipers equipped with an integrated parking brake system. P-3
  • Install wheel, torque lug nuts, and make final checks and adjustments. P-1

Diagnose and repair power assist units. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Test pedal free travel with and without engine running; check power assist operation. P-2
  • Check vacuum supply (manifold or auxiliary pump) to vacuum-type power booster. P-2
  • Inspect the vacuum-type power booster unit for vacuum leaks; inspect the check valve for proper operation; determine necessary action. P-2
  • Inspect and test hydro-boost system and accumulator for leaks and proper operation; determine necessary action. P-3

Diagnose and repair miscellaneous (wheel bearings, parking brakes, electrical I, etc.) Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose wheel bearing noises, wheel shimmy, and vibration concerns; determine necessary action. P-1
  • Remove, clean, inspect, repack, and install wheel bearings and replace seals; install hub and adjust wheel bearings. P-1
  • Check parking brake cables and components for wear, rusting, binding, and corrosion; clean, lubricate, or replace as needed. P-2
  • Check parking brake operation; determine necessary action. P-1
  • Check operation of parking brake indicator light system. P-3
  • Check operation of brake stop light system; determine necessary action. P-1
  • Replace wheel bearing and race. P-1
  • Inspect and replace wheel studs. P-1
  • Remove and reinstall sealed wheel bearing assembly. P-2

Diagnose and repair antilock brake and traction control systems. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Identify and inspect antilock brake system (ABS) components; determine necessary action. P-1
  • Diagnose poor stopping, wheel lock-up, abnormal pedal feel or pulsation, and noise concerns caused by the antilock brake system (ABS); determine necessary action. P-2
  • Diagnose antilock brake system (ABS) electronic control(s) and components using self-diagnosis and/or recommended test equipment; determine necessary action. P-1
  • Depressurize high-pressure components of the antilock brake system (ABS). P-3
  • Bleed the antilock brake system’s (ABS) front and rear hydraulic circuits. P-2
  • Remove and install antilock brake system (ABS) electrical/electronic and hydraulic components. P-3
  • Test, diagnose and service ABS speed sensors, toothed ring (tone wheel), and circuits using a graphing multimeter (GMM)/digital storage oscilloscope (DSO) (includes output signal, resistance, shorts to voltage/ground, and frequency data). P-1
  • Diagnose antilock brake system (ABS) braking concerns caused by vehicle modifications (tire size, curb height, final drive ratio, etc.). P-3
  • Identify traction control system components. P-3