GAUGE-VALVE CLEARANCE 0189660 - Caterpillar

Do not turn off the battery disconnect switch until the indicator lamp has turned off. If the switch is turned off when the indicator lamp is illuminated the Diesel Exhaust Fluid (DEF) system will not purge the DEF. If the DEF does not purge, DEF could freeze and damage the pump and lines.
Do not stop the engine immediately after the machine has been operated under load. This action can cause overheating and accelerated wear of engine components.After the machine is parked and the parking brake is engaged, allow the engine to run for 5 minutes at low idle before shutdown. This action allows hot areas of the engine to cool gradually.Note: With the key removed, a Delayed Engine Shutdown may operate. The engine will continue to operate for a time while the engine is in a cool down phase.Note: Wait 2 minutes before disabling all power with the battery disconnect switch. This period allows the DEF lines to purge fluid back to the DEF tank.For more information, refer to the following topics in the Operation Section of the Operation and Maintenance Manual:
“Stopping the Engine”
“Stopping the Engine if an Electrical Malfunction Occurs”