Question

While adjusting mechanical valve lifters, Tech A says when the valve clearance is checked on a cylinder, the piston in that cylinder should at TDC on the exhaust stroke.

Tech B says some mechanical valve lifters have removable shim pads available in various thicknesses to provide the proper valve clearance

-A
-B
-Both
-Neither

Answer 1

The correct answer is Both. When adjusting mechanical valve lifters, the valve clearance should be checked at TDC on the exhaust stroke. Some mechanical lifters have removable shim pads for adjusting the valve clearance.

Step-by-step explanation:

Tech A is correct. When adjusting mechanical valve lifters, the valve clearance should be checked when the piston in that cylinder is at top dead center (TDC) on the exhaust stroke. This is because the exhaust valve is fully closed at this position, ensuring that there is no interference between the valve and the piston. By adjusting the valve clearance at TDC on the exhaust stroke, the correct amount of clearance can be set.

Tech B is also correct. Some mechanical valve lifters have removable shim pads available in various thicknesses. These shims are used to adjust the valve clearance and provide the proper clearance between the valve and the lifter. By removing or adding shims of different thicknesses, the valve clearance can be adjusted to the manufacturer's specifications.