TM-9-2815-220-24 Maintenance Manual for AVDS-1790-2CA AVDS-1790-DA and AVDS-1790-2DR Engines Download
Page 301 of 1563
TM 9-2815-220-24 FUEL BACKFLOW VALVE TEST 0046 00 WP 0046 00-1 THIS WORK PACKAGE COVERS: Test INITIAL SETUP: Tools: General mechanic’s tool kit (item 121, WP 0176) Expendable and Durable Items: Air supply Container for fuel, minimum one gallon capacity Personnel Required: Track Vehicle Repairer (1) 63H10 Equipment Conditions: Engine removed from vehicle and placed on a flat stationary surface The fuel backflow valve is a dual purpose valve. • It incorporates a check valve that prevents pressurized fuel generated by the purge pump (wobble pump) from back flowing into the primary fuel filter. • It incorporates a by-pass valve that limits the fuel pressure to the manifold heaters. The most notable symptom produced by a non-functioning backflow valve is a non- functioning manifold heater. To determine if your backflow valve is functioning properly, perform the following test. TEST 1. Check free flow of valve (1). a. Disconnect hose (2) [fuel out of valve] from outlet fitting (3). b. Provide a suitable container to catch fuel. c. Provide 0.5 psi at valve inlet fitting (4). d. Fuel must flow freely at 0.5 psi from outlet fitting (3). 4 2 3 1