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MEDBRAKE SYS
The brakes of a veh have to absorb all the energy given to
the veh by the engine and due to the momentum of the veh
This energy must then be wasted or dissipated
In most veh brakes, the energy is absorbed by friction,
converted into heat and the heat dissipated by the stream
of air passing under and around the veh
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MEDBRAKE SYS
The front brakes play a greater part in stopping the car than
the rear ones, because braking throws the car weight
forward on to the front wheels.
Many cars therefore have disc brakes, which are generally
more efficient, at the front and drum brakes at the rear
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MEDHYD BRAKES
Hyd brakes are applied by the driver through an actuating
sys using hyd principles to multiply the brake pedal force
In a brake actuating sys, the enclosed vessel is a master cyl
and a wh cyl with connecting lines and hoses
Any pressure applied to the master cyl is transmitted
undiminished to each wh cyl
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MEDHYD BRAKES
As the brake pedal is depressed, the rod pushes the piston
of the master cyl, thus applying pressure to the brake fluid
Moving through pipes and hoses to the whl cyl, the fluid
forces apart the cyl pistons, and the later press the shoes
against the brake drums
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MEDDISK BRAKES
A disc brake has a disc that turns with the wh
The disc is connected by a caliper, in which there are small
hyd pistons worked by pressure from the master cyl
The pistons press on friction pads that clamp against the
disc from each side to slow or stop it
The pads are shaped to cover a broad sector of the disc
There may be more than a single pair of pistons, esp in dual-
circuit brakes
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MEDDRUM BRAKES
A drum brake has a hollow drum that turns with the wh
Its open back is covered by a stationary back plate on which
there are two curved shoes carrying friction linings
The shoes are forced outwards by hyd pressure moving
pistons in the brake's wh cyl
The linings is pressed against the inside of the drum to slow
or stop it
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MEDDRUM BRAKES
Each brake shoe has a pivot at one end and a piston at the
other
A leading shoe has the piston at the leading edge relative to
the dir in which the drum turns
It is simpler but less powerful than the two-leading-shoe
system, and is usually restd to rear brakes
Shoe travel is kept as short as possible by an adjuster
Brakes have automatic adjustment by means of a ratchet
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