A-A-52476 Pump, Engine Priming, Hand-Driven, (Nonaircraft) EngineThis CID covers a hand-operated, displacement type for engine priming and a replacement kit. The pump is capable of delivering 5 to 20 centimeters (cc) of fuel per stroke in 5 cc increments determined by the number of sleeves installed. This pump is intended for installation in, or as auxiliaries to, the fuel systems of vehicles, and other military equipment powered by internal-combustion engines, either during production, or in the field as part of winterization or other kits.

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A-A-52476

b. Design and construction. Design and construction of the engine priming pump shall be in accordance with figure 1 and as specified herein. The capacity of the engine priming pump, in cubic centimeters, is determined by the number of installed sleeves (see figure 1). When specified (see note b) the replacement kit shall be in accordance with Army drawing 5702557, including instruction sheet.

c. Performance. Unless otherwise specified, tests shall be performed with gasoline conforming to type II of MIL-G-3056 and under room ambient temperature conditions except for low temperature operation.

d. Pumping resistance. The force against the knob or handle to start and to maintain plunger movement in either direction at any point in the normal stroke (not including that required to disengage from the retainer or holding device) shall not exceed 20 pounds while being operated for 55 strokes.

e. Pump delivery (capacity). Pump delivery shall not be less than 95 percent (%) of the nominal capacity required (see figure 1). The pump shall be connected to a test fuel supply and to a reservoir or receiver with suitable intake and discharge lines and fittings. The pump shall be operated at a uniform rate of 20 full strokes per minute for 5 minutes, pumping test fuel against a 20 inch suction head and a 54 inch discharge head. The next 10 strokes shall be counted and delivery volume measured for average delivery per stroke.

f. Leakage. The pump shall evidence no air leakage when subjected to 20 pounds per square inch (psi) air pressure applied to the inlet and outlet ports, respectively, with the opposite port plugged or blocked off, while submerged in water. The plunger shall be drawn back to the end of the suction stroke, and shall then be subjected to a side force of 5 pounds in several directions. Rising air bubbles shall indicate leakage.

g. Low temperature operation. The pump shall meet the pump delivery requirements specified in salient characteristics (SC) 6D when operated at minus 65 degrees Fahrenheit (°F). The pump shall be filled with dry cleaning solvent or combat grade gasoline as specified in 2.3 and shall be conditioned for 48 hours at a temperature of minus 65 + 7°F.

h. Fuel effects. The pump shall operate properly, without impairment of subsequent functioning, after exposure to hydrocarbon test fluids. The pump shall be operated in accordance with SC e. (pump delivery) for one minute using hydrocarbon test fuel consisting of trimethylpentane and toluene mixture. This pumping shall be repeated at 50 minute intervals using 8 cycles (see SC e.). A rest period of 16 hours shall follow, during which time the test fuel shall remain in the pump. The pumping shall then be resumed until an additional 8 cycles have been completed. The plunger cap and packings shall subsequently show no evidence of swelling, shrinking, cracking or discoloration.

i. Endurance. Pump shall conform to SC e (pump delivery [capacity]) after it has been subjected to 20 full strokes per minute for a period of 5 hours per day until 20 hours of operation have been reached. During periods of nonoperation the pump shall remain filled with fuel.

j. Lubrication. The plunger shall be coated with grade 30 engine oil suitable for preservation and break-in.