natef task area a5 - grafton school district...natef task area a5 brake systems c. drum brake...

NATEF Task Area A5 Brake Systems

• A. General Brake System Diagnosis

• B. Hydraulic System Diagnosis & Repair

• C. Drum Brake Diagnosis & Repair

• D. Disc Brake Diagnosis & Repair

• E. Power Assist Diagnosis & Repair

• F. Wheel Bearing, Parking Brake, Electrical D & R

• G. Antilock Brake & Traction Control Systems

NATEF Task Area A5 Brake Systems A. General Brake System Diagnosis

Complete work order to include customer information, vehicle identifying information, verify customer concern, related service history, cause, correction.

A5.A.1

Have the Customer Sign & Date the R.O.


Identify & interpret brake system concern; determine necessary action. A5.A.2


Research applicable vehicle and service information, such as brake system operation, vehicle service history, service precautions, and technical service bulletins.

A5.A.3


Locate and interpret vehicle and major component identification numbers (VIN, vehicle certification labels, calibration decals)

A5.A.4

NATEF Task Area A5 Brake Systems B. Hydraulic System Diagnosis & Repair

Diagnose pressure concerns in the brake system using hydraulic principles (Pascal's Law).

A5.B.1


Measure pedal applied height; determine necessary action. A5.B.2


Check master cylinder for internal and external leaks and proper operation; determine necessary action.

A5.B.3


Remove, bench bleed, and reinstall master cylinder. A5.B.4


Diagnose poor stopping, pulling or dragging concerns caused by problems in the hydraulic system; determine necessary action.

A5.B.5


Inspect brake lines, flexible hoses, and fittings for leaks, restrictions, kinks, rust, cracks, bulging or wear; tighten loose fittings and supports; determine action.

A5.B.6


Fabricate & install brake lines (double flare & ISO types); replace hoses, fittings, & supports as needed.

A5.B.7


Select, handle, store, and install brake fluids to proper level. A5.B.8


Inspect, test, replace metering (holdoff), proportioning (balance), pressure differential, & combination valves.

A5.B.9


Inspect, test, replace, and adjust height (load) sensing proportioning valve. A5.B.10


Inspect, test, replace, and adjust height (load) sensing proportioning valve. A5.B.11


Bleed (manual, pressure, vacuum or surge) brake system A5.B.12


Flush hydraulic system. A5.B.13

NATEF Task Area A5 Brake Systems C. Drum Brake Diagnosis & Repair

Diagnose poor stopping, noise, pulling, grabbing, dragging or pedal pulsation; determine necessary action.

A5.C.1


Remove, clean (w/proper safety procedures), inspect, & measure brake drums; service/replace as needed.

A5.C.2


Mount brake drum on lathe; machine braking surface. A5.C.3


Remove, clean, and inspect brake shoes, springs, pins, clips, levers, adjusters/self adjusters, other related brake hardware, and backing support plates; lubricate and reassemble.

A5.C.4


Remove, inspect, and install wheel cylinders. A5.C.5


Preadjust shoes & parking brake before installing brake drums or drum/hub assemblies & wheel bearings.

A5.C.6


Install wheel, torque lug nuts, and make final checks and adjustments. A5.C.7

NATEF Task Area A5 Brake Systems D. Disc Brake Diagnosis & Repair

Diagnose poor stopping, noise, pulling, grabbing, dragging or pedal pulsation; determine necessary action.

A5.D.1


Remove caliper from mounting; clean & inspect for leaks & damage; determine necessary action.

A5.D.2


Clean and inspect caliper mounting and slides for wear and damage; determine necessary action.

A5.D.3


Remove, clean, and inspect pads and retaining hardware; determine necessary action.

A5.D.4


Disassemble and clean caliper assembly; inspect parts for wear, rust, scoring, and damage; replace seal, boot, and damaged or worn parts.

A5.D.5


Reassemble, lubricate, and reinstall caliper, pads, and related hardware; seat pads, and inspect for leaks.

A5.D.6


Clean, inspect, and measure rotor with a dial indicator and a micrometer; follow manufacturer’s recommendations in determining need to machine or replace.

A5.D.7


Remove & reinstall rotor A5.D.8


Refinish rotor on vehicle. A5.D.9


Refinish rotor off of vehicle A5.D.10


Adjust calipers with integrated parking brake system. A5.D.11


Install wheel, torque lug nuts, and make final checks and adjustments. A5.D.12

NATEF Task Area A5 Brake Systems E. Power Assist Units Diagnosis & Repair

Test pedal free travel with & without engine running; check power assist operation. A5.E.1


Check vacuum supply (manifold or auxiliary pump) to vacuumtype power booster.

A5.E.2


Inspect the vacuumtype power booster unit for vacuum leaks; inspect the check valve for proper operation; determine necessary action.

A5.E.3


Inspect & test hydraulically assisted power brake system for leaks and proper operation; determine necessary action.

A5.E.4


Measure and adjust master cylinder push rod length. A5.E.5

NATEF Task Area A5 Brake Systems F. Wheel Bearing, Parking Brake, Electrical Diagnosis & Repair

Diagnose wheel bearing noises, wheel shimmy, and vibration concerns; determine necessary action.

A5.F.1


Remove, clean, inspect, repack, & install wheel bearings, replace seals; install hub & adjust wheel bearings.

A5.F.2


Check parking brake cables and components for wear, rusting, binding, and corrosion; clean, lubricate, and replace as needed.

A5.F.3


Check parking brake operation; adjust as needed. A5.F.4


Check operation of parking brake indicator light system. A5.F.5


Check operation of brake stop light system; adjust and service as needed. A5.F.6


Replace wheel bearing and race. A5.F.7


Inspect and replace wheel studs A5.F.8


Remove and reinstall sealed wheel bearing & hub assembly A5.F.9

NATEF Task Area A5 Brake Systems G. Antilock Brake & Traction Control Systems

Identify & Inspect antilock brake system (ABS) components; determine necessary action.

A5.G.1


Diagnose poor stopping, wheel lockup, abnormal pedal feel or pulsation, and noise concerns caused by the antilock brake system (ABS); determine necessary action.

A5.G.2


Diagnose antilock brake system (ABS) electronic control(s) and components using selfdiagnosis and/or recommended test equipment; determine necessary action.

A5.G.3


Depressurize highpressure components of the antilock brake system. A5.G.4


Bleed the antilock brake system’s (ABS) front and rear hydraulic circuits. A5.G.5


Remove and install antilock brake system (ABS) electrical/electronic and hydraulic components.

A5.G.6


Test, diagnose, and service ABS speed sensors, toothed ring (tone wheel), and circuits using a graphing digital multimeter (GMM)/digital storage oscilloscope (DSO) (includes output signal, resistance, shorts to voltage/ground, and frequency data).

A5.G.7


Diagnose antilock brake system (ABS) braking concerns caused by vehicle modifications (tire size, curb height, final drive ratio, etc.).

A5.G.8


Identify traction control/vehicle stability control system components A5.G.9

natef task area a5 - grafton school district...natef task area a5 brake systems c. drum brake...

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