you need manifold vacuum for the brake booster.. (intake manifold)
On the left-lower part of the intake manifold (if facing the motor.) The hose runs underneath the manifold.
check the brake booster vacumme hose,its the hose than runs from the intake to the brake booster. if its leaking air the car stall when you hit the brakes or has no power
From the booster, to a vacuum source on the engine.
Any place there is a vacuum hose, under the hood and under the dash. Also the Power Brake Booster hose. The Booster diaphragm may also be busted. An Intake Manifold Gasket or the Intake Plenum gasket are sources of a vacuum leak.
The cause of hard brake pedal is malfunctioning brake booster. Check the hose from the intake manifold going to the brake booster for cracks or leakage, replace if necessary. Check the one way valve located in the middle of that hose, make sure the valve opens when you put pressure on one port.. If all those mentioned are ok, the booster itself needs to be replaced....
The type of brake system with vacum assist will have a large diameter hose from somewhere on the intake manifold to the brake booster. The type of brake system with hydro-boost will have hoses from the power steering pump to the brake booster.
Normally the vacuum line from a brake booster goes to the intake manifold of a gasoline engine. Sometimes other lines will be tied in to feed vacuum to cruise control pots or 4x4 actuators, but the main hose will be larger.
the brake vacuum booster connects to the intake manifold all by itself and the PCV valve hose should hook directly to your carburetor.
Well there are lots of possible reasons, BUT Li key it is a vacuum leak, either the hose of Brake booster, and or intake is / has a leaking vacuum line.
Vacuum leak on hose from intake manifold to brake booster.
There should be a BIG vaccume port just behind the carburetor that is screewed into the intake and that's where it goes. Some carburetors had a vaccume port on the back of them that had a medal line that screewed into the back of the carburetor and the booster hose slid onto it. It can go in either place.