Brakes Flashcards
List 3 qualities that brake fluid must have
A high boiling point
A constant fluidity at different temperatures
Doesn’t affect the rubber or metal components of the brake system
What does brake fluid do?
Transfers the force of the pedal to the wheel brake cylinders and/or calipers
What happens in brake fluid boils?
What is this called?
There are small bubbles in in fluid which can be compressed, so the brakes are less effective
Vapour lock
What does hygroscopic mean?
Attracts water
Why must brake fluid be hygroscopic?
What is the disadvantage of this?
To bind the free water particles to brake fluid
The brake fluid’s boiling point is reduced
What is the DOT
The department of transport
What is dry boiling point?
What is wet boiling point?
Which one is lower?
The boiling point of break fluid without water bonded to it
The boiling point of break fluid with 3% water
Wet boiling point
What is kinetic energy converted to during braking?
Heat
What does the piston seal do?
What could its function be compared to?
It is in between the brake caliper and piston and deforms during braking, then returns to its original shape after
A spring, which pushes the brake piston back to its original position
List 3 components that make up a brake pad
Metal backing plate
Brake lining
Damping material
What is damping material used for on a brake pad?
To reduce vibration and noise
What 2 things have occurred when there is glazing on the brake lining?
The brake lining has overheated
The bonding material has formed a glass-like layer on the surface of the brake lining
What is a low coefficient of friction?
How do you find out that brake pads are extremely worn without checking them visibly?
(2 ways)
The acoustic indicator, which makes a scraping noise when rubbed against by the brake disc
The electric wear indicator will send a signal to the dashboard light
How do you find out that brake pads are extremely worn by checking them visibly?
(2 ways)
The groove in the centre will not be visible
By measuring them
Give another name for brake glazing?
Brake fading
Other than to check if brake pads are worn, what is the other function of the groove in the centre?
To drain heat and water
Give another name for hand brake
Give another name for foot brake
Parking brake
Service brake
What does the master cylinder do?
Increase the pressure in the foundation system
What does the brake servo do?
Enhances braking power
What do the brake disc and brake drum do?
Slow the wheel
How is the hand brake operated?
Mechanically
What is the difference between a fixed caliper and floating caliper?
Fixed has 2 pistons and 2 brake pads.
Floating has 1 piston and 2 brake pads
What is the function of brake lines?
To ensure a rigid connection between the master cylinder and brake piston or caliper
What is the function of brake pipes?
To ensure a flexible connection between the brake lines and brake piston or caliper
What 2 things must be ensured when checking the brake system for leaks?
That the engine is idling
That the brake pedal is pressed down
How can you tell if the brake hose is twisted?
There’s sometimes a white line that runs along the brake hose
List 5 of the most common brake hose problems
Twisted
Worn
Fine cracks
Leakage at the coupling
Bulges
List 2 functions of the brake master cylinder
To convert pedal force into hydraulic pressure
To move brake fluid to the wheel brake cylinders
What happen to the brake cup seals when the brake pedal is released?
They open a hole
Why do brake cup seals open a hole when you release the brake pedal?
To prevent a vacuum from forming, which would increase the chance of air getting into the system
List 2 components of an electric parking brake system
Button
Electric motor and control unit
Where is the brake pressure limiter always located?
In the rear wheel brake circuit
Name the 2 types of brake pressure regulators
Brake pressure regulator with a fixed switching point
Load-dependent brake pressure regulator
