How do power brakes work on a diesel?

Answer 1

look here it has pics to help with the info

http://www.dmv.ca.gov/pubs/cdl_htm/sec5_a.htm#air

for gas engines they use a hydro vac system

http://chevy.tocmp.com/1947truckshop/47ctsm0514.htm

Answer 2

I think you are talking about engine brakes.
On a gasoline engine, if you let off the gas, the throttle plate closes and creates a vacuum which slows the engine down. That's why you can downshift when going down hills and let the engine slow you.
Diesels have no throttle, so if you downshift the wheels will just drive the engine faster unless there is another mechanism to slow the engine down. There are two major types of diesel brakes. The first it the notorious jacobs brake (jake brake), which opens the exhaust valves at TDC on one or more cylinders. This turns those cylinders essentially into air compressors and slows the engine down. The second is an exhaust brake: a throttle-like plate in the exhaust stream which can be closed to dramatically increase exhaust backpressure and slow the engine that way.
Engine brakes are used to take the load off of the wheel brakes and prevent overheating, glazing, and consequently large runaway vehicles.

Answer 3

How Do Power Brakes Work

Answer 4

If you mean a big rig type diesal, they are air brakes. They have a compressor that is driven off the motor, this compressor forces air into a pressurized container. When you apply the brakes, the equivalent amount of air is released into the air lines leading to the brakes, that is need to slow or stop the truck. This is a simple way of explaining a complex system, so don't let anyone get bent out of shape over it ok??

Answer 5

big rigs are stopped by springs by a component called an
air chamber that is fixed to all four wheels.
Inside the airchamber is a powerful spring on one side and
pushing a piston aginst an area of compressed air provided
by an air pump mounted on the engine.
As the air pressure rises the piston is forced aginst the spring releasing the brakes from the drums.
When the brakes are applied an amount of air is released
from the pressurized system giving the springs in the airchambers dominance therefore the brakes are applied.
If you refering to a Jake brake it is a way of stopping a truck
without brakes, its a process of stopping a vehicle using the
the engine cylinders as an air pump onto itself in a moment of deceleration creating drag to a desired speed.

Answer 6

If you are refering to servo assisted brakes some diesel engines have a vacuum pump connected to the brake booster. I have a Ford Transit (UK) this has a pump built on to the alternator which provides the necessary vacuum to the booster as I believe diesel engines do not provide sufficient vacuum on their own.