Brake Adjustment and Maintenance Flashcards

What are the signs of worn or damaged brake shoes a driver should look for during inspection?

Answer: Shiny metal surfaces, no visible lining material, or lining contaminated with oil

Warning signs include worn-through lining exposing metal, oil contamination, and cracked or loose lining material — all are out-of-service conditions.

What is the recommended frequency for professional brake inspections on commercial vehicles under federal regulations?

Answer: Per manufacturer specs and federal requirements, typically every 12,500 miles or 6 months

Federal regulations and manufacturer specifications typically require brake inspections every 12,500 miles or 6 months, whichever comes first.

What is the purpose of brake shoe return springs in a drum brake assembly?

Answer: To retract brake shoes away from the drum when brakes are released

Return springs pull the brake shoes away from the drum when brakes are released, preventing drag that would cause heat buildup and premature wear.

What can happen if brake chambers are not properly sealed and moisture enters the chamber?

Answer: Moisture causes corrosion of internal components including the diaphragm and push rod, leading to failure

Moisture inside brake chambers causes corrosion of the diaphragm, push rod, and other internal components, leading to premature failure.

How does very cold weather affect air brake system performance?

Answer: Moisture in lines can freeze and rubber components can stiffen, potentially affecting brake function

In very cold weather, moisture in air lines can freeze and block air flow, and rubber diaphragms and seals can stiffen, potentially compromising brake function.

Why is it important to keep S-cam shafts and slack adjusters properly lubricated?

Answer: Proper lubrication prevents corrosion, reduces wear, and ensures smooth and consistent brake application

Proper lubrication of S-cam shafts, slack adjusters, and other mechanical components prevents corrosion and binding that can cause uneven or delayed brake application.