How do you adjest the valves on a c12 cat engine?

To adjust the valves on a C12 Cat engine, first, ensure the engine is cool and then remove the valve cover to access the rocker arms. Rotate the engine to bring the piston of the cylinder you’re adjusting to top dead center (TDC) on the compression stroke. Use a feeler gauge to check the clearance between the rocker arm and the valve stem, then adjust the valve lash by turning the adjustment screw until the correct clearance is achieved according to the manufacturer’s specifications. Finally, recheck the clearance after tightening the adjustment screw to ensure it remains within the specified range.