UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)
Table 1. Unit Preventive Maintenance Checks and Services (PMCS) for 621B Scraper.
NOT FULLY MISSION
Review all WARNINGs, CAUTIONs, and NOTEs before
performing PMCS on the 621B Scraper.
Unless otherwise indicated, perform all lubrication and
preventive maintenance with machine parked on level
ground, parking brake applied, transmission in N (Neu-
tral) and locked, scraper bowl lowered to the ground, and
engine shut down.
Perform Operator PMCS prior to or in conjunction with
Unit PMCS if:
a. There is a delay between daily operation of the machine
and Unit PMCS.
b. The regular operator is not assisting.
Never disconnect any charging system circuit or battery
when engine is running. A spark could cause an explosion
from the flammable vapor mixture of hydrogen and oxygen
released from the electrolyte in the battery. Failure to follow
this warning could result in personnel injury.
50 Hours or
Check electrolyte level and specific
gravity on maintainable batteries, and
perform battery load test on all batter-
ies (TM 9-6140-200-14).