Fuel Pump DESCRIPTION (See Pic)
Fuel is drawn from the fuel tank by the AC Fuel Lift
Pump which is driven by an eccentric on the engine
camshaft.
Fuel enters by the inlet connection (19) and is delivered
through the outlet connection (7).
The AC pump consists of two main bodies which clamp
a diaphragm between their outer flanges.
The lower body assembly comprises a rocker arm (8)
and link (11), both of which pivot on a pin (9) located in
the body. Attached to the link is the pull rod incor
porated in the diaphragm assembly (16). To protect
the diaphragm from crankcase oil splash, an oil seal is
located at the point in the lower body where the push
rod passes through. A return spring (15) is interposed between the underside of the diaphragm and the lower
body (12). This spring determines the pump output
pressure. A further spring (10). is fitted between the
rocker arm and the body for the purpose of ensuring
that the rocker arm is in constant contact with the
eccentric on the camshaft. Also incorporated in the
AC fuel lift pump is the hand priming mechanism (13).
Assembled in the upper body are two valve assemblies
(6 and 17). one being opened by suction. and the other by
pressure. Both valves are held in position by a common
retaining plate secured inside the upper body by two
screws.
Both inlet and outlet valve assem blies are identical in
construction and are renewable and interchangeable.
Also incorporated in the upper body is a filter gauze (5).
which is held in position with a domed metal top cover
(2) and gasket (1). which in turn is held by a centre
screw (3) through the cover into the upper body (18). |