REMOVAL & INSTALLATION
151 Four and 250 Inline Six Cylinder Engines
- Remove the rocker arm cover.
- Loosen the rocker arm until you can rotate it away from the pushrod, giving clearance to the top of the pushrod.
- Remove the pushrod. If you are replacing all of the lifters, it is wise to make a pushrod holder as mentioned under "Cylinder Head Removal." This will help keep the pushrods in order, as they MUST go back in their original positions.
- Remove the pushrod covers on the side of the block.
- Remove the lifter(s). A hydraulic lifter removal tool (GM part #J-3049 or equivalent) is available at dealers and most parts stores, and is quite handy for this procedure.
- Before installing new lifters, all sealer coating must be removed from the inside. This can be done with kerosene or carburetor cleaning solvent. Also, the new lifters must be primed before installation, as dry lifters will seize when the engine is started. Submerge the lifters in clean engine oil and work the lifter plunger up and down.
- Install the lifter(s) and pushrod(s) into the cylinder block in their original positions.
- Pivot the rocker arm back into its original position. With the lifter on the base circle of the camshaft (valve closed), tighten the rocker arm nut to 20 ft. lbs. Do not over torque. You will have to rotate the crankshaft to do the individual valves.
- Replace the pushrod covers using new gaskets. Replace the rocker arm cover, using a new gasket or sealer.
Valve lifters and pushrods should be kept in order so they can be reinstalled in their original position. Some engines will have both standard size and .010 in. oversize valve lifters as original equipment. The oversize lifters are etched with an "O" on their sides; the cylinder block will also be marked with an "O" if the oversize lifter is used.
- Remove the intake manifold and gasket.
- Remove the valve covers, rocker arm assemblies and pushrods.
- If the lifters are coated with varnish, apply carburetor cleaning solvent to the lifter body. The solvent should dissolve the varnish in about 10 minutes.
- Remove the lifters. On diesels, remove the lifter retainer guide bolts, and remove the guides. A special tool for removing lifters is available, and is helpful for this procedure.
- New lifter MUST be primed before installation, as dry lifters will seize when the engine is started. Submerge the lifters in clean engine oil and work the lifter plunger up and down.
- Install the lifters and pushrods into the cylinder block in their original order. On diesels, install the lifter retainer guide.
- Install the intake manifold gaskets and manifold.
- Position the rocker arms, pivots and bolts on the cylinder head.
- Install the valve covers, connect the spark plug wires and install the air cleaner.