Replacing broken valve springs or defective valve stem seals can be done with the
Cylinder Heads still in place with the sweet, the work necessitating two special tools and a compressed air supply. Detach the valve cover from the cylinder head and, if all the valve stem seals are to be changed, both of them. Subsequently strip the spark plug from the ICM cylinder affected, if changing all the seals strip all spark plugs. Slightly rotate the crankshaft so that the piston of the cylinder to be tested should be at the Top Dead Center in the compression stroke starting from cylinder no 1 and with the firing order as 1-6-5-4-3-2. All the
Rocker Arms,
Pushrods, as well as the support bar should be taken off the cylinder head. Insert an adapter to spark plug hole and fit an air hose from a compressed air drier apply 90 to 100 psi to check the valve staking. Put shop rags in the cylinder head holes so no parts go in Put the spring compressor on the spring and take off the keepers. Extract the spring retainer or rotator and the valve spring from the unit; thereafter, remove the valve stem seal from the valve guide. When air pressure cannot retain the valve shut, faces or seats are worn and require corresponding cylinder head fixations. The valve stem must be covered using a rubber band or electrician's tape in order to avoid it from going into the combustion chamber; pop the pressure. Hold the valve with your left hand and check less than stem for damage especially in the guide area. Bleed air pressure to maintain the valve in closed position, apply engine oil to the valve stems and fit in the new stem seal and nicely tap on it. Place the valve spring and damper; then the valve spring retainer to compress the spring and align the keeper with the groove with a drop of grease to secure it. Take off the air hose and remove the adapter on the spark plug hole, do the same step for the other cylinders with following the firing order. Last, put in the rocker arms, support bars, pushrods, valve cover(s), spark plug(s) reconnect the wires and fire up the engine and look for any sign of oil leaks and other strange noises.