TM-9-2320-387-10 HMMWV Operator Manual Download
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a. General. Vehicles operating in dusty or sandy areas require frequent servicing of the air filter and cooling system. NOTE For dusty conditions, a air cleaner, NSN 2940-01-302-8028, can be inserted in the air intake shield assembly at the discretion of the unit commander. b. Before Operation. (1) When operating on loose sand or soft ground, place transfer case shift lever in H/L (high/lock range) position and transmission shift lever in (overdrive). (2) Refer to para. 2-40 for techniques that can be used when operating on unusual terrain. c. During Operation. NOTE If additional power is needed to extract vehicle when mired in sand, place transmission in 1 (first) and transfer case in L (low range). After vehicle is extracted from mired condition, immediately return transfer case to H/L (high/lock range) position and transmission to (overdrive). (1) Frequently check air restriction gauge. If indicator shows red, park vehicle, stop engine, and refer to para. 3-15 for emergency air cleaner servicing. (2) If engine overheating occurs: (a) Park vehicle, and allow engine to idle. (b) Observe coolant temperature gauge for steady cooling. CAUTION Stop engine if coolant temperature gauge suddenly increases beyond approximately 230°F (110°C). Failure to comply will result in damage to engine. (c) If coolant temperature continues to increase or does not lower, stop engine. Perform applicable troubleshooting procedures in table 3-1. (3) Accelerate slowly so wheels will not spin and dig into sand. CAUTION Use a wrecker or second vehicle equipped with winch to recover vehicles mired in deep sand. Do not attempt to rock vehicles out of deep sand with quick transmission shift changes. Damage to transmission will occur. d. After Operation. (1) At end of daily operation, clean all sand from accelerator linkage and brake components. (2) Park vehicle in shade whenever possible to protect tires, soft tops, paint, wood, and seals from sun, dust, and sand. (3) If shade is not available, cover vehicle with tarpaulin. When entire vehicle cannot be covered, protect windows and hood with tarpaulin to prevent entry of sand or dust. (4) Vehicles completing operation in dusty, sandy areas must be lubricated and serviced by unit maintenance as soon as possible. TM 9-2320-387-10 2-108 2-43. OPERATING IN DUSTY, SANDY AREAS D D