Wednesday, April 16, 2014
How to Replace a Valve Lifter
Valve lifters are the actuators that open and close the valves on top of the engine, allowing the appropriate quantity of air into the cylinder. As with most moving parts under strain inside an engine; dirt, heat and friction take their toll over time, and the lifter will become worn, degrading its performance, and increasing the possibility of damaging other components.
Instructions
- 1
Remove the intake manifold and valve covers. Set them aside and take note of how all the bolts were positioned. Looking down into the engine, you should now be able to see the heads of the valves. But the push-rod will be passing over the top, preventing you from removing them.
2Remove the rocker arms and push-rods. With all the upper hardware on the engine disassembled, the cylinder head can be unbolted and lifted off the rest of the engine, giving you access to the tappets below. With the tappets released and removed, the lifters are accessible and ready to be removed.
3Grip the heads of the lifters with the needle-nose pliers and caully lift them up and out of their respective recesses. Lower the new lifters into the hole and replace the tappets. The tightness of the tappets is a trial and error process for mechanics who lack professional measuring equipment, so you may need to adjust them after the engine has been rebuilt. If the engine runs roughly, they need to be loosened. If they make a tapping noise, they need to be tightened.
4Replace the push-rods, rocker arms, valve covers and intake manifold, ensuring all bolts are properly tightened. Start the engine and allow it to run for five minutes, then stop it and make the necessary tappet adjustments. Repeat until the engine is running smoothly, allowing it to cool for several minutes between each run.
