Removal
Press the brake pedal 3-4 times to create the same pressure close to atmospheric in both cavities of the vacuum booster.
Remove the vacuum hose from the booster (see Fig. 9.50).
Disconnect the vacuum hose from the intake manifold. The vacuum hose may be connected to the intake manifold with a nut or a quick-release coupling. Depending on the type of hose fastening, either unscrew the nut or press the fastening ring and at the same time slowly pull the hose out of the intake manifold (see Fig. 9.51).
Check the condition of the vacuum hose and replace it if necessary.
Checking the vacuum valve
Check the valve for wear and damage. Replace if necessary. The valve can be checked by blowing air through it in both directions. It should allow air to pass from the brake booster to the vacuum hose.
Installation
Installation is carried out in the reverse order of removal.
(The original source of the publication is on the website: FordBook)