First disconnect the vacuum
Brake Booster check valve from its position on the booster unit before unclamping the check valve hose at its point of connection and removing both parts. For 4.8l, 5.3l, and 6.0l engine vehicles you need to take off the manifold sight shield then disconnect the vacuum Brake Booster hose from the engine area. To address the 4.3l engine setup you should unfreeze the vacuum Brake Booster hose from its engine connection. Use both 4.8l, 5.3l, and 6.0l and 4.3l engines for installing the vacuum Brake Booster hose by connecting it to the engine. Put back the manifold sight shield on engines with 4.8l 5.3l and 6.0l displacements before attaching the vacuum Brake Booster check valve to the hose using the vacuum Brake Booster hose clamp.