Master Cylinder Up To And Incl. Model 1970 - Saab V4 Service Manual

primary cup is
prevents the cup from
the piston The
2.
BRAKE SYSTEM
vacuum
Handbrake lever
Brake pedal
6. Broke cylinders
also has o dished rear
cup.
The springs return the pistons to the initial
no~ohnn
In their initial position, the pistons are retained
spring pressure and os a consequence the channels open
between the fluid container and the master cylinder.
When the brake pedal is depressed, the push-rod ac-
tuates the primary piston, making the inlet channel
between fluid container and cylinder close, and the
pressure in front of the primary piston rise which in turn
affects the secondary piston making it move and in this
way the some overpressure is obtained in front of both
pistons. Now brake fluid is forced out through the broke
lines to the wheel cylinders and puts the brakes into
action.
If a leakage occurs in the brake circuit served
primary piston, the spring is compr· >sed until the
piston contacts the secondary piston. Then the latter can
work normally.
At a leakage in the secondary piston circuit, the secon-
dar·, piston is pressed forward by the prima.y piston
and the spring, until the secondary piston strikes the
bottom of the cylinder. Then, brake fluid can be pressed
out into the undamaged circuit.
500-2
Nov. 1970