Page 1172 - Foton Workshop Manual - Auman EST-M

BR-40 Brake system – service brake (air pressure)

The function of the front brake air chamber is to input a different air pressure and produce a different thrust,
thus allowing the brake cam to drive the brake shoe and brake drum that produce a different-strength braking
force on the brake drum on the front axle.
In case of no braking, the return spring (5) drives the bearing disc (4) and the diaphragm (3) leftward against
the front housing (2). The entire brake air chamber is fixed onto the steering knuckle by bolts.
In case of braking, the compressed air enters from the air inlet (1) into the brake air chamber. The diaphragm
(3) moves rightward by overcoming the return spring under the air pressure, thus pushing rightward the push
rod (7) and the connecting fork (8) by means of the bearing disc (4). As a result, the braking adjusting arm
rotates around the camshaft by a certain angle. The braking adjustment arm rotates the brake cam, which
causes the brake shoe to open. The brake shoe presses the brake drum, thus producing a braking effect.

When the brake is released, the compressed air in the brake air chamber is emitted into the atmosphere via the
brake valve or quick release valve, the diaphragm (3), the bearing disc (4), and the push rod (7) move leftward
under the action of the return spring (5), thus rotating the braking high-speed arm in the opposite direction.
Then, the brake cam returns. Under the action of the return spring (5), the brake shoe closes up and the
braking effect is disabled.

BR-040