Hydraulics Power Brakes Test

What Is the function of the Brake Control Valve?

Routes pressure to and from the brakes

How is the Brake Control Valve actuated?

By pressing on the pedals

What is the function of the Debooster?

Decrease system pressure to brakes and increases volume of fluid flow

How does the Debooster decrease system pressure?

Through different sized pistons

What does the Shuttle Valve do?

Moves back and forth providing system pressure in emergencies

The Shuttle Valve provides emergency pressure in only the ______

brakes

The pistons in Multiple Disc Brakes push out against

discs

Where is the Torque Tube located?

in the middle of the multiple disc brakes, everything surrounds it

What are stators?

A type of disc that is stationary

Where are stators keyed?

On the internal diameter to the torque tube

What is the function of a stator?

They rub up against the rotors to stop

What are rotors?

A type of disc that rotates

Where are rotors keyed?

On the outside diameter to the wheel

Do the keys on stators and rotors need to be checked for wear?

Yes

What are common defects of discs?

dishing / coning

When inspecting the brakes you should also check the

pad thickness

What is a slip?

When the tire has intermittently lost traction with the runway surface

What is a skid?

When the tire has lost all traction with the runway surface

What happens when your wheels are locked up?

Wheels stop spinning and is either skidding or hydroplaning

What is hydroplaning?

When the tire is gliding across water – no contact with runway surface 

What is a Wheel Speed Sensor in an Anti-Skid System?

A sensor that sits in every axle

How does the wheel speed sensor work?

A flywheel is keyed to the wheel hub where it measures the wheel’s speed and sends the RPM to the control unit

What does the Control Unit do?

It monitors wheel speeds to make sure one isn’t decelerating more than the others

The control unit regulates pressure to prevent skids by sensing

the wheels gradually slowing down

How does the control unit provide locked wheel protection?

By determining all pressure goes to the locked wheel

How does the control unit provide touchdown protection?

By making sure the wheels aren’t locked on touchdown

What does the Antiskid control valve do?

It does the job that the control unit determines the system needs

Where is the antiskid control valve located?

between the brake valve and brake cylinder

What does the antiskid control valve control?

fluid