CAB AR 2301258 - Caterpillar

To prevent possible injury, do not use the starter motor to turn the flywheel.Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve clearance.
The initial valve lash adjustment for new engines and for rebuilt engines is scheduled at the initial 500 Service Hours.Check and adjust the valve lash at every 4000 service hours.Check and adjust the valve bridge before setting the valve lash. Ensure that the valve bridge is seated equally on both valve stems.
Operation of Caterpillar engines with improper valve adjustments will reduce engine efficiency. This reduced efficiency could result in excessive fuel usage and/or shortened engine component life.
Measure the valve clearance with the engine stopped. To obtain an accurate measurement, allow at least 20 minutes for the valves to cool to engine cylinder head and engine block temperature.
Illustration 1 g00291455If the valve clearance settings are within 0.08 mm ( .003 inch) of the nominal clearance, adjustment is not required. Refer to the following chart for valve clearance setting.
Table 1
VALVE CLEARANCE SETTING CHART
Intake Valve 0.38 mm (.015 inch)
Exhaust Valve 0.76 mm (.030 inch) Refer to your machine's Service Manual or your Caterpillar dealer for the complete valve adjustment procedure.