Breather Line and Suction Line Inspection

Special Tools Required 

• Fuel pressure gauge attachment set 07AAJ-S6MA150
• Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

1. Remove the access panel from the floor (see FUEL TANK UNIT REMOVAL AND INSTALLATION ).
2. Disconnect the suction line (A) from the fuel tank unit, and connect a vacuum pump/gauge, 0-30 in.Hg (B) to the hose as shown.
   Fig 1: Connecting Vacuum Pump/Gauge To Hose

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
3. Start the engine, and check the vacuum.
   • If there is vacuum, go to step  4.
   • If there is no vacuum, replace the fuel filter (see FUEL FILTER REPLACEMENT ).
4. Turn the ignition switch OFF.
5. Attach the fuel pressure gauge set. Connect a vacuum pump/gauge, 0-30 in.Hg (A) to the suction line (B), and apply vacuum to the line.
   • If the line holds vacuum, check for blockage in the suction line. If there is blockage, replace the line.
   • If the line does not hold vacuum, go to step  6.
   Fig 2: Connecting Vacuum Pump/Gauge To Suction Line
   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Disconnect the breather line (A). Attach the fuel pressure gauge set, then plug the suction line (B) with a rubber cap (C).
   Fig 3: Attaching Fuel Pressure Gauge Set To Suction Line

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Attach the fuel pressure gauge set. Connect a vacuum pump/gauge, 0-30 in.Hg (A) to the suction line (B), and apply vacuum to the line.
   • If the line holds vacuum, check for blockage in the suction line and the fuel tank vapor recirculation tube. If there is blockage, replace the fuel tank (see FUEL TANK REPLACEMENT ). If the fuel tank vapor recirculation tube is OK, replace the suction line.
   • If the line does not hold vacuum, go to step  8.
   Fig 4: Connecting Vacuum Pump/Gauge To Suction Line
   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Connect a vacuum pump/gauge, 0-30 in.Hg (A) to the filler side of the breather line (B), and apply air pressure to the line.
   • If the air pressure holds, check for blockage between the suction line and the filler neck on the breather pipe, and replace the part that is causing the blockage.
   • If the air pressure does not hold, go to step  9.
   Fig 5: Connecting Vacuum Pump/Gauge To Filler Side Of Breather Line

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
9. Remove the rubber cap from the suction line, and reconnect the breather pipe to the suction line.
10. Attach the fuel pressure gauge set. Connect a vacuum pump/gauge, 0-30 in.Hg (A) to the suction line (B), and apply pressure to the line.
    • If the air pressure holds, the breather line and the suction line are OK.
    • If the air pressure does not hold, check for a vacuum leak in the suction line, and replace the suction line if necessary.
    Fig 6: Connecting Vacuum Pump/Gauge To Suction Line

    Courtesy of AMERICAN HONDA MOTOR CO., INC.