780 V6-2849cc 2.8L SOHC B280F (1987)
Vacuum Brake Booster: Description and Operation
Full Braking
The connection between the rear of the diaphragm and centre of the valve assembly is opened when the valve piston seat separates from the valve disc,
allowing air at atmospheric pressure to enter the chamber at the rear of the diaphragm. Since vacuum is present at the front of the diaphragm, the
diaphragm and control housing travel forward, increasing the force on the front pushrod. The illustration shows the position of the servo at maximum
braking.