Disconnect the breather line (A), then plug the suction joint (B) with a rubber cap (C).
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 breather line between the fuel tank and the suction joint. If there is blockage,
replace the fuel tank.
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 15
.
Remove the rubber cap from the suction line, and reconnect the breather pipe to the suction line.
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.