UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS) - CONTINUED
Table 1. Unit Preventive Maintenance Checks and Services (PMCS) for 621B Scraper - Continued.
NOT FULLY MISSION
Inspect for loose electrical connec-
tions and unusual noise or bearing
Inspect for bad connection, damaged
wiring, loose electrical connections or
evidence of burning. Replace starting
motor assembly as necessary (WP
Inspect valves and linkage. Look for
bent levers and control arms and worn
bushings (WP 0325 00).
Inspect for leaks or damage. Replace
Inspect for scuffing, strain, wear, leaks
or loose fittings. Tighten loose fit-
Explosions of air-inflated earth moving tires can be a
result of heat-induced gas combustion inside the tires. The
heat generated by welding or heating rim components,
external fire or excessive use of brakes can result in gas-
eous combustion. A tire explosion is much more violent
than a blowout. The explosion can propel the tire, rim and
final drive components as far as 1,500 ft (460 m) or more.
Both the force of the explosion and flying debris can cause
injury or damage to equipment. All personnel should be
aware of this danger and the actions to take to minimize
the risk (TM 5-3805-248-10).
Improper use of inflation equipment can result in tire
blowout or rim failure.
a. Check for adequate tread and
replace if tread depth is insufficient
(WP 0302 00 and WP 0303 00).
b. Check for proper inflation of 60 psi
(276 kPa) for tractor 40 psi (414
kPa) for scraper.