SSANGYONG RODIUS 2004.09 Manual page 443

4) Master Cylinder
5) Brake Booster
The brake booster is a power assist device for brake system.
It relieves the pedal depressing force by using the pressure difference between the vacuum
pressure generated by vacuum pump in intake manifold and the atmospheric pressure.
▶Pressure distribution at working
When depressing the brake pedal, the push
rod (1) in booster pushes the poppet (2) and
valve plunger (3). The poppet (2) pushes the
power piston seat (5) resulting in closing the
vacuum valve (9). The chamber (A) and (B)
in power cylinder are isolated and the valve
plunger (3) is separated from the poppet (2).
And then the air valve (6) opens and air
flows into the chamber (B) through filter.
Then, the power piston (5) pushes the
master cylinder push rod (7) to assist the
brake operation.
The brake master cylinder is designed to
convert the force from the brake master
cylinder to the high hydraulic pressure.
The brake system uses the tandem type
master cylinder with in-line 2 pistons.
The in-line 2 pistons generate the hydraulic
pressure.
The piston cup on the piston keeps the sealing
conditions in cylinder and prevents the oil
leaks.
The hydraulic pressure generated by the
primary piston is delivered to the front wheels,
and the hydraulic pressure generated by the
secondary piston is delivered to the rear
wheels.
▶Pressure distribution after working
When releasing the brake pedal, the valve
plunger (3) returns back to the original
position by return spring (4) and the air valve
(6) closes. At this time, the vacuum valve (9)
opens and the pressure difference between
chamber (A) and (B) in power cylinder is
eliminated. Accordingly, the power piston (5)
returns back to original position by the
reaction of master cylinder (10) and the
diaphragm return spring (8).
08-7
4830-01
BRAKS SYSTEM
RODIUS 2004.09