MAINTENANCE EVERY 100 OPERATING HOURS 28. MAINTENANCE EVERY 100 OPERATING HOURS All maintenance operations to be performed after 10 and 50 hours of operation fall also into this maintenance category. 28.1 DRAINING THE WATER SEPARA- TOR, REMOVING WATER AND DIRT DEPOSITS Keep a container ready for collecting the liquid from the water separator (1). 1 - Screw out the drain plug (2). 2 - Let the water run off. 3 - Screw in the drain plug and tight it. 4 - Check for tightness. 161 1 2 75 231