Brake Systems Flashcards
7 cards from real Automotive and Mechanics practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Brake Systems flashcards as text
The 'discard dimension' stamped on a brake rotor indicates which specification?
Answer: The minimum thickness at which the rotor must be discarded
The discard dimension is the minimum allowable thickness; rotors worn or machined below this spec must be replaced as they cannot safely dissipate braking heat.
A spongy or soft brake pedal that gradually sinks toward the floor most likely indicates which condition?
Answer: Air trapped in the hydraulic brake lines
Air is compressible unlike brake fluid, so air trapped in the lines creates a soft, spongy pedal feel and reduces hydraulic pressure transfer.
Which tool is most commonly used to retract a disc brake caliper piston when installing new brake pads?
Answer: C-clamp or dedicated caliper piston tool
A C-clamp or dedicated caliper piston tool compresses the piston back into its bore to create clearance for the thicker new brake pads.
When bleeding brakes on a four-wheel vehicle using the gravity or pressure method, which wheel is typically bled FIRST?
Answer: Rear right (furthest from master cylinder on most vehicles)
The standard sequence starts at the wheel furthest from the master cylinder—typically the rear right—to push air progressively through the entire system.
What energy source does a conventional vacuum-assisted brake booster use to multiply the driver's pedal effort?
Answer: Engine intake manifold vacuum
A vacuum brake booster uses the low pressure (vacuum) from the engine's intake manifold to create a pressure differential across a diaphragm that amplifies pedal force.
A brake drum must be replaced rather than resurfaced when it has:
Answer: Exceeded its maximum allowable inside diameter specification
Brake drums machined or worn beyond their maximum inside diameter specification lack sufficient metal mass to absorb and dissipate braking heat safely.
A persistent grinding or metal-on-metal noise that occurs only when the brakes are applied most commonly indicates:
Answer: Brake pads worn completely through to the metal backing plate
When friction material is fully worn away, the steel backing plate contacts the rotor directly, producing a grinding sound and rapidly damaging the rotor surface.