GMC 12482063 Valve Seal

Valve spring and faulty valve stem seal can be easily replaced without undressing of the cylinder head-two special tools and compressed air are needed in average. The first step can be made by disconnecting the spark plugs and the valve covers and with the help of the crankshaft to adjust the position of the first piston at the top dead center of the compression stroke. Turn the rocker arms of the number one piston removing the spark plug and thread the adapter into the hole, you will then connect the air hose to a compressed air source. With the use of the cylinder compression gauge, the Schrader valve, needs to be removed from the fitting, and the auto parts stores commonly provide the air hose adapter. Spray compressed air into the cylinder to 'lock' the valves into position, and wedge shop rags into the cylinder head holes surrounding the valves in order to prevent loose items from falling into the vehicle's engine. Cover the retainer with your hand and gently tap on top of the retainer to break the seal and then place the valve spring compressor on the spring then you use the small needle nose pliers or magnet to remove the keepers. Extract the valve spring and retainer and realise that if the valve cannot be retained with air pressure, then the cylinder head would have to be unbolted for fixing. Pull the old valve stem seals out with needle-nose pliers; you may want to wind a rubber band or that type of auto tape around the top of the valve stem to hold the stem from falling and look at the stem for any signs of damage. Reapply some pressure to retain the valve, and tighten it accordingly; new valve stem seal needs to be fitted with the help of appropriate one for intake as well as the exhaust valves, up to the described depth. Place the spring and retainer, slightly preload the valve spring assembly so that the keepers can be placed in and a little grease put to hold the keepers in place. Remove the air hose and pull the adapter out from the spark plug hole, then proceed on other cylinders making certain that the piston reaches the top dead center on the compression stroke before applying air pressure. Last of all, the rocker arm assemblies and valve covers are replaced, then start the engine and check whether there is oil leakage around the engine and unusual sound during its initial running and allow the engine to run for not less than five minutes before putting it into further operation.