Hi Guys. Has the hose that comes off the plenum and goes to the brake booster seems to have some sort of valve in it? What does it do? Thanks Col
There is no valve in the hose, but the hose runs to a check valve and then to the brake booster. The check valve is closed when the manifold is under pressure and open when under vacuum. Without it you would have a vacuum assisted, and boost resisted brake pedal.
