Page 1180 - Foton Workshop Manual - Auman EST-M

BR-48 Brake system – service brake (air pressure)

The rear brake air chamber is a composite one, which produces a braking force on the rear axle's main brake
and in addition allows for parking braking and emergency braking.
The main brake air chamber and the parking brake air chamber are integrated into a whole. The main brake air
chamber adopts a diaphragm brake mechanism and the parking brake air chamber adopts a brake device based
on spring-stored energy air bleeding. The air pressure in the parking brake air chamber is applied onto the
piston (5) when entering into the air chamber from B, and it is opposite to the thrust of the spring (6). If the air
pressure is higher than 600kPa, the piston's compression spring moves leftward to the extreme with the result
that the brake is disabled. If the air in the air chamber is completely bled via B, then the piston is pushed
rightward by the spring (6), and the hollow push rod drives the main brake air chamber's push rod to extend
out to produce a braking force. The maximum braking strength depends on the pretightening force of the
spring. If the input pressure of B is lower than 600kPa, the piston and the push rod also extend out to produce
a braking force. However, the braking strength is directly proportional to the inputted air pressure
value. Different air pressure values can produce different braking effects of different strengths. So, the parking
brake air chamber is also an emergency brake air chamber.

BR-048