fail - safe is the difference between air brakes and hydraulic brakes.
what is the difference between air brakes and hydraulic brakes?
fail - safe
section::::advantages.





















































air brakes are used as an alternative to hydraulic brakes which are used on lighter vehicles such as automobiles. hydraulic brakes use a liquid (hydraulic fluid) to transfer pressure from the brake pedal to the brake shoe to stop the vehicle. air brakes are used in heavy commercial vehicles due to their reliability. they have several advantages for large multi-trailer vehicles:





















































bullet::::- the supply of air is unlimited, so the brake system can never run out of its operating fluid, as hydraulic brakes can. minor leaks do not result in brake failures.
air brake (road vehicle)
the term 'power hydraulic brakes' can also refer to systems operating on very different principles where an engine-driven pump maintains continual hydraulic pressure in a central accumulator. the driver's brake pedal simply controls a valve to bleed pressure into the brake units at the wheels, rather than actually creating the pressure in a master cylinder by depressing a piston. this form of brake is analogous to an air brake system but with hydraulic fluid as the working medium rather than air. however, on an air brake air is vented from the system when the brakes are released and the reserve of compressed air must be replenished. on a power hydraulic brake system fluid at low pressure is returned from the brake units at the wheels to the engine-driven pump as the brakes are released, so the central pressure accumulator is almost instantly re-pressurised. this makes the power hydraulic system highly suitable for vehicles that must frequently stop and start (such as buses in cities). the continually circulating fluid also removes problems with freezing parts and collected water vapour that can afflict air systems in cold climates. the aec routemaster bus is a well-known application of power hydraulic brakes and the successive generations of citroen cars with hydropneumatic suspension also used fully powered hydraulic brakes rather than conventional automotive brake systems.
hydraulic brake