Genuine 1986 Chevrolet Caprice Intake Manifold

1986 Chevrolet Caprice Parts Questions & Experts Answers

• Q: What steps should be followed when removing and replacing the intake manifold in V8 engine on 1986 Chevrolet Caprice?

  A: If the engine has been removed from the car, disregard the following steps which do not apply. For vehicles equipped with air conditioning, carefully examine the routing of the A/C hoses and the mounting of the compressor; you may be able to remove the intake manifold without disconnecting the A/C system, but if in doubt, consult a certified dealer or refrigeration specialist to have the system depressurized, ensuring not to disconnect the A/C hoses while under pressure. Begin by disconnecting the negative battery cable, draining the coolant from the radiator, and removing the air cleaner assembly. Next, disconnect the upper radiator hose and the heater hose from the intake manifold, followed by the accelerator linkage at the carburetor, ensuring to catch any spillage when disconnecting the fuel inlet hose and plugging it to prevent dirt entry. Disconnect all other hoses connected to the carburetor, identifying each with numbered tape to avoid confusion during reassembly. Remove the distributor, securing the distributor cap with spark plug wires against the firewall, and if equipped with an external coil from 1969 to 1974, disconnect and mark the wiring. Disconnect the vacuum hose leading to the power brake booster if applicable, remove the upper bracket for the alternator, and the air conditioning compressor bracket at the intake manifold. Remove the intake manifold-to-cylinder head attaching bolts, counting to ensure all have been removed, then lift the manifold with the carburetor free from the engine without prying on the mating surfaces. If replacing the intake manifold, transfer applicable accessories such as the carburetor, temperature or oil pressure sending unit, water outlet and thermostat, heater hose and water pump hose adapter fittings, EGR valve, emission system TVS switches, carburetor choke assembly, and ignition coil and bracket for models from 1969 to 1974. Before installing the manifold, place clean lint-free rags in the engine cavity and thoroughly clean the engine block, cylinder heads, and manifold gasket surfaces, removing all extra gasket material and sealing compound. Install new front and rear seals to the engine block using RTV or an equivalent sealant, extending the bead of sealant about ½-inch up the sides of each cylinder head to seal and retain the side gaskets. Position new manifold side gaskets on each cylinder head, using sealant around the water passages, ensuring proper mating with the front and rear seals. Lower the intake manifold into position carefully, torque the attaching bolts to specifications, and install the remaining components in reverse order of removal. Finally, fill the radiator with coolant, start the engine, check for leaks, and adjust the ignition timing and carburetor idle speed as necessary.