Recent

  • Show all results for ""
CDL Air Brakes Part 2 Flashcards
53 Questions
100 Views

CDL Air Brakes Part 2 Flashcards

Created by
@AdmiringInspiration

Questions and Answers

The air pressure should not drop more than ___ psi single, ___ psi combination during an applied leakage test.

3, 4

What is a supply pressure gauge used for?

Guages tell you how much pressure is in the air tanks

The service brake system applies and releases the parking brakes when you use the parking brake control.

False

When air tank pressure rises to around 125 - 130 psi, the governor stops the compressor from pumping air.

<p>True</p> Signup and view all the answers

What are the maximum leakage rates for an air brake system?

<p>Less than 2 psi single, 3 psi combination for one minute</p> Signup and view all the answers

The safety relief valve protects the air tanks and the rest of the system from building too much pressure.

<p>True</p> Signup and view all the answers

How do you test the low pressure warning signal?

<p>Turn the electrical power on and step on and off the brake pedal to reduce air tank pressure.</p> Signup and view all the answers

The air pressure should not drop more than ___ psi single, ___ psi combination during a static leakage test.

<p>2, 3</p> Signup and view all the answers

What are the maximum leakage rates for an air brake system in one minute?

<p>Less than 2 psi single, and 3 psi in combo</p> Signup and view all the answers

A slack adjuster is a lever that connects the brake chamber push rod with the return spring.

<p>False</p> Signup and view all the answers

The safety valve in an air tank is usually set to open and release air at 150 psi.

<p>True</p> Signup and view all the answers

Letting up on the brake pedal increases the air pressure and releases the brakes.

<p>False</p> Signup and view all the answers

Which direction does the S-cam force brake shoes when brakes are applied?

<p>It presses them against the inside of the brake drum</p> Signup and view all the answers

After applying your brakes fully in a combination vehicle, your maximum air loss in one minute should be no greater than?

<p>4 lbs per square inch</p> Signup and view all the answers

What can legally hold a parking or emergency brake in position for a truck, truck tractor or bus?

<p>Spring pressure</p> Signup and view all the answers

On S-cam brakes, what happens to the air when you push the brake pedal?

<p>Air pressure forces out the push rod and moves the slack adjuster</p> Signup and view all the answers

Where are foundation brakes found?

<p>At each wheel</p> Signup and view all the answers

Why should you be in the proper gear before starting down a hill?

<p>So you only have to apply the brake just hard enough to feel a definite slowdown</p> Signup and view all the answers

With dual air systems, the air pressure should build from ___ to ___ psi in 45 seconds.

<p>85, 100</p> Signup and view all the answers

The air compressor governor controls?

<p>When air is pumped into the air tank</p> Signup and view all the answers

An air tank is equipped with a drain valve to remove?

<p>Water and oil</p> Signup and view all the answers

Why does air braking take more time than hydraulic braking?

<p>Because it takes time for air to flow through the lines to the brakes</p> Signup and view all the answers

What are the two types of air tank drains?

<p>Manually operated and automatic</p> Signup and view all the answers

How often should you check the alcohol evaporator in cold weather?

<p>Check the alcohol container and fill up as necessary every day</p> Signup and view all the answers

What happens if you must make an emergency stop?

<p>You should brake so that you stay in a straight line and can steer</p> Signup and view all the answers

You should know that your brakes are fading when?

<p>You have to push harder on the brake pedal to control your speed on a downgrade</p> Signup and view all the answers

Why drain water from the compressed air tanks?

<p>Water can freeze in cold weather and cause brake failure</p> Signup and view all the answers

To check the slack adjusters on S-cam brakes, you should?

<p>Wear gloves and pull hard on each slack adjuster</p> Signup and view all the answers

In a combination vehicle, brakes released, the maximum air released is?

<p>Less than 3 lbs per square inch</p> Signup and view all the answers

After applying brakes fully, what is the maximum air loss in one minute for single vehicles?

<p>3 lbs per square inch</p> Signup and view all the answers

The brake pedal in an air brake system controls?

<p>The air pressure applied to put on the brakes</p> Signup and view all the answers

Where will you find the drain valve for each air tank?

<p>In the bottom of the tank</p> Signup and view all the answers

Compressed air is stored?

<p>In the storage tank</p> Signup and view all the answers

Single vehicle, brakes released: maximum air leakage rate in one minute is?

<p>Less than 2 lbs per square inch</p> Signup and view all the answers

What are the three brake systems?

<p>Service, Parking, emergency brakes</p> Signup and view all the answers

The emergency brake system uses parts of?

<p>The service and parking brake system</p> Signup and view all the answers

A dual air brake system?

<p>Has 2 air brake systems and 1 set of controls</p> Signup and view all the answers

An air pressure gauge shows?

<p>How much pressure you are applying to the brakes</p> Signup and view all the answers

What are the three types of low air pressure warning devices?

<p>A red light, buzzer, wigwag</p> Signup and view all the answers

What can you check to see if the spring brakes come on automatically?

<p>(Engine off) Step on and off brakes till brake knob pops out; pressure falls between 20-40 psi</p> Signup and view all the answers

What are two other names for the brake pedal?

<p>Foot valve or treadle valve</p> Signup and view all the answers

The first thing to do when low air pressure warning comes on?

<p>Stop and safely park as soon as possible</p> Signup and view all the answers

An emergency brake is required on commercial vehicles, must be held on by mechanical force, could be activated by the loss of air pressure.

<p>True</p> Signup and view all the answers

What happens when a brake lining is pushed against the inside of the drum?

<p>This causes heat which slows the vehicle and creates heat</p> Signup and view all the answers

You should use the parking brake?

<p>Any time you park</p> Signup and view all the answers

The application pressure gauge shows the driver how much pressure?

<p>Is being applied to the brakes</p> Signup and view all the answers

A fully charged air system typically has?

<p>125 psi</p> Signup and view all the answers

If oil and water collect in the air tanks, what can happen to the brakes?

<p>The brakes could fail</p> Signup and view all the answers

When you put on the brake by pushing down the brake pedal?

<p>Air pressure is applied to the brake pads</p> Signup and view all the answers

A wedge brake pushes a wedge between the shoe linings and the drum.

<p>false</p> Signup and view all the answers

What activates a stop light pressure?

<p>Air pressure</p> Signup and view all the answers

To make a smooth safe stop, hold down the clutch while using the brake pedal to control pressure to the brake system.

<p>False</p> Signup and view all the answers

What is the purpose of ABS?

<p>To maintain control of the vehicle during an emergency</p> Signup and view all the answers

Study Notes

Air Brake System Basics

  • Air pressure should not drop more than 3 psi in single, 4 psi in combination, and 6 psi in a combination of 3 during an applied leakage test.
  • Supply pressure gauges indicate the amount of pressure in the air tanks.
  • The service brake system does not apply or release parking brakes; this is false.
  • The air compressor governor stops pumping air when tank pressure reaches 125-130 psi.

Leakage Rates

  • Maximum leakage rates for an air brake system:
    • Less than 2 psi for single vehicles and 3 psi for combination vehicles within one minute during tests.
  • Static leakage test shows air pressure should not drop more than 2 psi single, 3 psi combination, and 5 psi combination of 3 in one minute.

Safety Mechanisms

  • Safety relief valves prevent air tanks from exceeding pressure limits, typically set at 150 psi.
  • Low air pressure warning signals should activate before tank pressure drops below 60 psi.

Brake Components and Functionality

  • Slack adjusters do not connect the brake chamber push rod to the return spring; this is false.
  • The S-cam mechanism forces brake shoes against the drum when brakes are applied.
  • Foundation brakes are located at each wheel, crucial for vehicle stopping.

Vehicle Operation and Maintenance

  • Proper gear selection before descending a hill allows minimal brake application.
  • Dual air systems should build from 85 to 100 psi in 45 seconds.
  • Air compressor governors regulate when the compressor pumps air into storage tanks.

Air System Maintenance

  • Air tanks must have drain valves to eliminate water and oil, preventing freezing and brake failure in cold conditions.
  • Check the alcohol evaporator daily in cold weather to ensure effective brake functionality.

Emergency Procedures

  • In an emergency stop, apply brakes firmly to maintain control.
  • Brake fading occurs when more pressure is needed to control speed on downgrades.

Air System Operations

  • Draining water from compressed air tanks is crucial to prevent brake system issues.
  • Brake pedal controls air pressure for braking; it is also referred to as the foot valve or treadle valve.
  • The application pressure gauge informs how much pressure is being applied to brakes.

ABS and Safety

  • An emergency brake is required on commercial vehicles and must engage mechanically or upon air pressure loss.
  • ABS (Anti-lock Braking System) helps maintain vehicle control during emergencies.

Additional Key Facts

  • When the brakes are applied, air pressure pushes brake pads against the lining, generating heat to slow the vehicle.
  • Spring pressure is legally required to hold the parking or emergency brakes in place for trucks and buses.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

Test your knowledge on air brakes with these flashcards. This quiz covers key concepts like applied leakage test limits and the function of supply pressure gauges. Enhance your understanding of CDL requirements and air brake systems.

More Quizzes Like This

Alabama CDL General Knowledge
77 questions

Alabama CDL General Knowledge

LuxuriantOstrich avatar
LuxuriantOstrich
CDL Class A Air Brakes Test Flashcards
40 questions

CDL Class A Air Brakes Test Flashcards

PatriLavender avatar
PatriLavender
Texas CDL Air Brakes Flashcards
32 questions

Texas CDL Air Brakes Flashcards

TalentedFantasy1640 avatar
TalentedFantasy1640
CDL Air Brakes Flashcards
11 questions

CDL Air Brakes Flashcards

MesmerizingBongos avatar
MesmerizingBongos
Use Quizgecko on...
Browser
Open
Browser
Browser