TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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Note. Components of the fuel check valve are not available as replacement parts. Therefore, no further disassembly is required. Figure 6-242. Deleted. b. Cleaning, Inspection and Repair. Refer to paragraphs 6-2, 6-3, and 6-4. c. Assembly. Refer to figure 6-241. d. Test and Adjustment (fig. 6-243). (1) Fill valve with test fluid, MIL-F-7024A Type II, and apply a pressure of ½ psi to port marked “FREE FLOW” (fuel inlet from primary fuel filter). The check valve must open at this pressure. Valve operation can be deter- mined when fluid flows from the fuel pump outlet port. (2) Apply a pressure of 85 to 95 psi to the heater pump inlet port. The check ball must bypass fluid at this pressure. Adjust socket head adjusting screw (F, fig. 6-242) to obtain this opening pressure. (3) Plug the fuel pump outlet port, and the heater pump outlet port, and apply a pressure of 100 psi at heater pump inlet port. There should be no fuel leakage from the “FREE FLOW” port. (4) If the valve fails to pass either test, replace entire valve assembly. Figure 6-243. Fuel check valve flow diaphragm. 6-204