Cadillac 12639087 Manifold, Intake

Before the removal of the intake manifold it is required that you pull the cable off the negative terminal of the battery and also lose the fuel system pressure. Subsequently, exclude the air filter housing outlet duct and label, then, disconnect all engine wiring harnesses which affect the intake manifold extraction, by releasing all the harness clip lock, and bundle all strands away from the operation area. Remove the hose connected to the canister purge solenoid if it is already connected, the fuel line connected to the fuel rail and the PCV hose connected to the intake manifold. Then, remove all other electrical connectors or vacuum hoses which are connected to the intake manifold or throttle body. Ease the intake manifold mounting bolts by a quarter turn, and depending on the engine model, they should be easily removable, be very careful not to use any tools to pry between the manifold and the heads as this may cause damage the gasket sealing surfaces. By pulling it over the heads, then unbending any still connected as the intake manifold is lifted off the engine. For Valve Lifter Oil Manifold (VLOM) removal, other components that must be detached include the fuel pump insulator, the fuel rail and injectors, and the balance shaft sprocket; the VLOM assembly mounting bolts are then removed and the gasket, in case it is still serviceable, should be saved. On mating, the places where the cylinder heads, block and the manifold sit should be absolutely clean: rid of all gasket debris by gentle scraping off at most. Wipe the ribs of the new gasket and place it over the cylinder block, if the VLOM has been removed, replace it and fasten the bolts to the recommended torque. Place the new gaskets in the appropriate position on the intake manifold so that they fit into place and cover the intake port holes; then, with equal care, position and fit the manifold in the space provided. Screw in the bolts and fasten them according to the sequence and torque value but with great care to avoid tightness that will lead to gasket leakage. Last of it, the rest of the installation if done in the reverse manner to removal and once the engine has been started, look out for vacuum leaks at the joints of the intake manifold.

Before removing the intake manifold, one has to first disconnect the wire from the negative terminal of the car battery and also discharge the fuel system. After that, one should take out the air filter housing outlet duct and the alternation. Remove and label all engine wiring harness that are going to be restricted by the intake manifold, remove all harness retainers and clips and secure those harness which are removed out of your way. Remove the power brake vacuum hose connection to the booster and the vacuum hose to the canister purge solenoid, the fuel line to the fuel rail, and the PCV hose to the intake manifold. Remove any of the remaining electrical connections or vacuum hoses connected to the intake manifold or to the throttle body. Unfasten the intake manifold mounting bolts ¼ turn at a time in the reverse sequence or the tightening sequence until they are easily removable by hand and you may need to use pry bar to separate the gasket if it sticks hard on the surfaces without harming the gasket sealing surfaces. Pull-forward the manifold and then unplug all the wiring harness connectors; further, detach the intake manifold and look for other hooks as it is being lifted. On the 6.0L models when changing a manifold, the fuel rail and the injectors should be removed. For installation, make sure the surfaces of the cylinder heads, block and manifold to be contacted with the gaskets are devoid of all forms of residues of the previous gasket material but should not be scraped of smooth. Dry clean the mating surfaces with safety solvent and duster and vacuum any dirt from the area. The tapped holes should be chased with a tap of the corresponding size; the holes should then be cleaned with compressed air. Place the new gaskets as they slide and click into position and will fit into the intake port holes. Ensure the manifold is placed correctly and fix the bolts and tighten them in a proper sequence and to the necessary torque, ensure do not over tighten to avoid gasket leak. The rest of the installation procedure is performed in the reverse order to the removal one; after that, start the engine and check vacuum leaks at the joints of the intake manifold.