SUPPORT AS-ENGINE 4N4631 - Caterpillar

If pressurized air is not supplied to the air shutoff, the shutoff will not operate in an emergency situation. Do not shut off the air supply to the air shutoff. Ensure that the air shutoff has a supply of pressurized air.
Note: Some air starting motors are connected to the same source of compressed air that activates the air shutoff.
Turn the air supply to the starting motor OFF. DO NOT apply a load to the engine or increase the rpm until the oil pressure gauge indicates a minimum of 160 kPa (23 psi) at low idle rpm.Check the gauges during the warm-up. Complete a walk-around inspection. Check for leaks and unusual noises.
Ensure that the gauges indicate normal ranges for the engine rpm. After verifying that the engine systems are normal, engage the driven equipment.Begin operating the engine at low load. Continue to check the gauges and the driven equipment. Operate the engine at a low load until the engine reaches normal operating temperatures.
After normal oil pressure is reached and the jacket water temperature reaches 65 °C (149 °F), the engine may be operated at full load. Increase the load, as needed.