MIL-T-62491 Trucks, Wrecker: 4540 To 40 820 Kilograms 5-Ton To 45-Ton Lifting Capacity, Modified CommercialThis specification covers all commercial, non-tactical wreckers procured for military use. Vehicles procured under this specification are commercial items which are warranted by the manufacturer as specified in acquisition documents.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49

MIL-T-62491C

control valves to insure positive and safe control of all operations and to provide protection in the event of loss of hydraulic power. All components of the hydraulic system shall be positioned or shielded to prevent hazardous fluid contact with heated surfaces or electrical apparatus.

3.5.15.1 Hydraulic pump(s). Hydraulic pump(s) with required pressure and flow capacities to operate hydraulically powered components shall be provided. The pump(s) shall have sufficient capacity to operate all hydraulic components and shall provide for operation of at least

three functions simultaneously. The hydraulic pump(s) shall be driven as specified in 3.4.5.5. The pumping system shall include an adjustable pressure relief valve or unloading valve with a range of adjustment which allows raising, lowering, extending and retracting the boom with any working

or test load specified herein.

3.5.15.2 Hydraulic fluid reservoir. A hydraulic fluid reservoir shall be provided, with sufficient capacity to hold the required volume of hydraulic fluid, plus not less than 10 percent expansion space. The reservoir shall be provided with a filler opening and a vented filler cap located to facilitate filling the tank from a 3.78 L (one-gallon) container using a funnel. The

vented filler cap shall have means to prevent fluid from splashing out of the tank during movement of the vehicle. The filler cap shall be attached to the tank by a corrosion-resistant chain.

Provision shall be made for draining the reservoir. The reservoir drain shall be located so that the fluid will not drain on other components of the vehicle, and shall allow recovery of the fluid in a container. The reservoir shall have a corrosion-resistant metal plate indicating the type of hydraulic fluid furnished. The reservoir shall indicate the maximum fluid level in the reservoir

with the boom retracted for travel and the hydraulic lines and components full of fluid. A sight level or dip stick gage shall be furnished to enable the level of the fluid in the reservoir to be observed. The tank shall be clean.

3.5.15.3 Hydraulic fluid. Unless otherwise specified, hydraulic fluid conforming to the manufacturer's standard or recommended requirements shall be provided in the hydraulic system. When specified (see 6.2), hydraulic fluid conforming to MIL-H-83282 shall be provided in the hydraulic system. A corrosion-resistant metal plate located near the hydraulic system fill opening shall be furnished stating "CAUTION: USE HYDRAULIC FLUID CONFORMING TO

MIL-H-83282 ONLY."

3.5.15.4 Oil filter and strainers. A full-flow type, 10-micron discharge oil filter in the return line to the reservoir shall be provided. A 100-mesh suction line strainer in the suction line from the reservoir shall be provided. The filter and the suction strainer shall be easily accessible for periodic cleaning, or for replacement of the filter cartridge. The filter and the strainer shall have sufficient capacity to allow the pump to deliver the rated flow required for all operations specified herein.