Usps Automotive Exams 943,944,945 (WITH
CORRECT AND VERIFIED ANSWERS ) ACTUAL
EXAM!!
Distributorless Ignition System (DIS) - ANSWER☑️⭐-system that replaces the traditional distributor with
individual coils, one for each spark plug or a coil for every two cylinders, eliminating the need for a
distributor cap and rotor.
Mechanical Systems - ANSWER☑️⭐-(ETBSSE) Engine, Transmission, Suspension, Steering, and Electrical.
Braking Internal Process - ANSWER☑️⭐-press pedal applying force to the fluid in the master cylinder,
pressure is transferred through break lines to Calipers (Disk) or Wheel Cylinders (Drum), pushes break
pads or shoes against rotor or drum.
Disc Breaks, Rotor, Break Pads, Caliper, Break Fluid - ANSWER☑️⭐-Used in Modern Vehicles. The break
pad presses against the rotor to create friction. The force is transferred through the rotor to the wheel.
Rotor - flat circular metal disc.
Break Pads - friction materials that press against rotor
Caliper - houses break pads and hydraulics that move pads
Break Fluid - transmits force from break pedal to pads through a closed loop of brake lines
Break Fluid Full Breakdown - ANSWER☑️⭐-- clear slightly yellow liquid
- helps create hydraulic pressure needed to operate brakes.
- lubricates the components to reduce wear and prevent corrosion.
- providing a barrier between metal parts inside the braking system and the environment preventing
rust and corrosion.
- absorbs and dissipates the heat generated during braking, prevents system from overheating.
, What degrades Brake Fluid? What does degradation cause? - ANSWER☑️⭐-moisture lowers the boiling
of fluids, boiling brake fluid creates air bubbles through the system lowering pressure leading to break
fade.
Drum Breaks, Break Shoes, Break Drum, Wheel Cylinder - ANSWER☑️⭐-Used in Old Vehicles especially
on rear wheels. A Break Shoe presses against the inside of a rotating Break Drum creating friction.
Break Shoes - curved friction materials that press against drum
Break Drum - rotating part that will be slowed/stopped
Wheel Cylinder - a hydraulic piston that uses break fluid to cause action between Shoe and Drum.
Types of Brake Fluid Breakdown - ANSWER☑️⭐-DOT Glycol:
3. most common in Older vehicles, glycol-based, Hydroscopic (absorbs moisture from the air over time)
4. has a higher boiling point, for vehicles that experience higher braking temperatures
5.1. highest boiling point of DOT fluids, used in performance or heavy duty vehicles.
DOT Non-Glycol:
5. silicone-based, common in classic cars (really old) or military vehicles, dose not absorb moisture,
incompatible with glycol-based systems.
Non-DOT: mineral oil and other silicone-based fluids
Bleeding the Brakes (Two-man) Breakdown - ANSWER☑️⭐-- raise vehicle and locate caliper bleed valve
- loosen valve and attach hose to displace fluid
- second person slowly presses and hold brake pedal
- open valve while pedal is held to release fluid and air
- close valve before letting go of pedal
- fill master cylinder as needed
Anti-lock Braking System (ABS) - ANSWER☑️⭐-prevents wheels from locking up during emergency
braking by continuously monitoring wheel rotation and adjusting break pressure accordingly
Common Brake Issues Breakdown - ANSWER☑️⭐-Squeaking - worn break pads, moisture, dust or debris
CORRECT AND VERIFIED ANSWERS ) ACTUAL
EXAM!!
Distributorless Ignition System (DIS) - ANSWER☑️⭐-system that replaces the traditional distributor with
individual coils, one for each spark plug or a coil for every two cylinders, eliminating the need for a
distributor cap and rotor.
Mechanical Systems - ANSWER☑️⭐-(ETBSSE) Engine, Transmission, Suspension, Steering, and Electrical.
Braking Internal Process - ANSWER☑️⭐-press pedal applying force to the fluid in the master cylinder,
pressure is transferred through break lines to Calipers (Disk) or Wheel Cylinders (Drum), pushes break
pads or shoes against rotor or drum.
Disc Breaks, Rotor, Break Pads, Caliper, Break Fluid - ANSWER☑️⭐-Used in Modern Vehicles. The break
pad presses against the rotor to create friction. The force is transferred through the rotor to the wheel.
Rotor - flat circular metal disc.
Break Pads - friction materials that press against rotor
Caliper - houses break pads and hydraulics that move pads
Break Fluid - transmits force from break pedal to pads through a closed loop of brake lines
Break Fluid Full Breakdown - ANSWER☑️⭐-- clear slightly yellow liquid
- helps create hydraulic pressure needed to operate brakes.
- lubricates the components to reduce wear and prevent corrosion.
- providing a barrier between metal parts inside the braking system and the environment preventing
rust and corrosion.
- absorbs and dissipates the heat generated during braking, prevents system from overheating.
, What degrades Brake Fluid? What does degradation cause? - ANSWER☑️⭐-moisture lowers the boiling
of fluids, boiling brake fluid creates air bubbles through the system lowering pressure leading to break
fade.
Drum Breaks, Break Shoes, Break Drum, Wheel Cylinder - ANSWER☑️⭐-Used in Old Vehicles especially
on rear wheels. A Break Shoe presses against the inside of a rotating Break Drum creating friction.
Break Shoes - curved friction materials that press against drum
Break Drum - rotating part that will be slowed/stopped
Wheel Cylinder - a hydraulic piston that uses break fluid to cause action between Shoe and Drum.
Types of Brake Fluid Breakdown - ANSWER☑️⭐-DOT Glycol:
3. most common in Older vehicles, glycol-based, Hydroscopic (absorbs moisture from the air over time)
4. has a higher boiling point, for vehicles that experience higher braking temperatures
5.1. highest boiling point of DOT fluids, used in performance or heavy duty vehicles.
DOT Non-Glycol:
5. silicone-based, common in classic cars (really old) or military vehicles, dose not absorb moisture,
incompatible with glycol-based systems.
Non-DOT: mineral oil and other silicone-based fluids
Bleeding the Brakes (Two-man) Breakdown - ANSWER☑️⭐-- raise vehicle and locate caliper bleed valve
- loosen valve and attach hose to displace fluid
- second person slowly presses and hold brake pedal
- open valve while pedal is held to release fluid and air
- close valve before letting go of pedal
- fill master cylinder as needed
Anti-lock Braking System (ABS) - ANSWER☑️⭐-prevents wheels from locking up during emergency
braking by continuously monitoring wheel rotation and adjusting break pressure accordingly
Common Brake Issues Breakdown - ANSWER☑️⭐-Squeaking - worn break pads, moisture, dust or debris
