Bleeding Fuel System; Bleeding Air From Fuel Filters (Wire-Element Type) - Mitsubishi S12U Operation & Maintenance Manual

Chapter 3
OPERATION

Bleeding Fuel System

When fuel overflows from the air vent plug, wipe
thoroughly with a cloth. Spilled fuel is a fire haz-
ard.
After bleeding, lock the priming pump cap
securely. If the cap is not locked tightly, the
priming pump can be damaged, causing fuel
leakage that may lead to a fire.
Closing all air vent plugs before locking the priming
pump cap disallows the priming pump cap from
returning to the original position due to internal pres-
sure.
Bleed air from the location closest to the fuel tank
that are the fuel filter (wire-element type), fuel filter
(center-bolt type), then the fuel feed pipe.
Bleeding Air from Fuel Filters
(Wire-Element Type)
Replace to a new part if there is a damage on the air
vent plug, thread area of bracket or sealing washer.
1 Loosen the air vent plug on the fuel filter (wire-
element type) by rotating about 1.5 turns.
2 Loosen the priming pump cap by turning counter-
clockwise and move it back and forth.
3 When there are no air bubbles in the fuel flowing
from the air vent plug, tighten the air vent plug to
the specified torque.
Bleeding Air from Fuel Filters
(Center-Bolt Type)
Replace to a new part if there is a damage on the air
vent plug, thread area of bracket or sealing washer.
1 Loosen the air vent plug on the fuel filter (center-
bolt type) by rotating about 1.5 turns.
2 Move its priming pump cap back and forth.
3 When there are no air bubbles in the fuel flowing
from the air vent plug, tighten the air vent plug to
the specified torque.
3-2
[Unlock]
Turn counterclockwise
[Priming]
Move back and force
Priming pump cap
fig.3-1 Priming pump operating method
Bracket
fig.3-2 Bleeing air from fuel filters
(wire-element type)
Air vent plug and
sealing washer
fig.3-3 Bleeding air from fuel filters
(center-bolt type)
[Lock]
Press the cap
and turn clockwise
Air vent plug and
sealing washer
Air vent plug and
sealing washer