Cadillac 12580678 Intake Manifold

Start by removing and installing intake manifolds. Disconnect the negative battery cable. The lower intake manifold has to be removed to be able to access it. Remove the alternator and air filter housing outlet duct. Take note of all wires connected to the intake manifold that must be disconnected when removed including harness retainer and clips. Disengage the power brake vacuum hose, canister purge solenoid hose, fuel line from the fuel rail and PCV hose from the intake manifold. There are any remaining electrical connectors or vacuum hoses attached to either throttle body or intake manifold located then disconnect them as well. Loosen the mounting bolts for the intake manifold in reverse order until they can be removed by hand. In such a case, you may have to use a pry bar to gently break the gasket seal. Lift and remove the intake manifold taking care not to miss anything that may still be attached. When installing, carefully clean off gasket surfaces without aggressively scraping which could damage sealing surfaces then wipe them down with safety solvent. Clear out debris from bolt holes using tap and compressed air, snap new gaskets onto manifold ensuring they are firmly seated, cautiously place it down, then proceed with tightening of bolts according to specified torque values in sequence given that is indicated in manufacturer's instruction manual. Avoid over tightening. Finally reverse steps taken earlier, start car engine up and check if there is any leakage at any of the joints in this area on a vacuum basis after all this is done.