TM 5-5420-226-20-1 Symptom-2 DETAILED TROUBLESHOOTING PROCEDURE VEHICLE OPERATION -  POWERPLANT, STARTING T (Continued) \ 2 Check for   free    fuel   flow    from    main   fuel    line   at connection between tubing and   flexible hose. First Technician (Top Deck) l   Have    powerplant removed (page 5-2). First Technician (Engine Compartment) l   Disconnect flexible hose    from metal fuel   supply line. l   Place    a  suitable    container or   rags    under fuel   line   to catch any   fuel. Second Technician (Operator’s Station) l   Set   MASTER BATTERY switch ON. l   Set   FUEL PUMPS switch ON    for   approximately 10 seconds, then    set   FUEL PUMPS switch OFF. l   Set   MASTER BATTERY switch OFF. / Did  fuel   flow    freely from    metal    fuel   supply line? 1 n FRONT OF    ENGINE COMPARTMENT FLEXIBLE HOSE ( l   Clear    clogged flexible hose by   blowing with   compressed air. l   Install    female quick disconnect half   to   flexible hose. l   Connect flexible hose    to metal fuel   supply line. l   if  this   does    not   work,    replace flexible hose. 4-150 TA106839