Cadillac 60 Series 1963 Shop Manual page 237

10-2
wire to ground. The fuel outlet line is integral
with tank float unit assembly. It has a special
saran mesh filter on the inlet end. The filter has
a self-cleaning action, provided by the sloshing
action of the gasoline.
The fuel outlet line is attached to the gage as-
sembly on the top center of the tank and extends
along the inside of the right rocker panel to the
fuel pump, Fig. 10-3.
The fuel pump is mounted on the engine front
cover. The pump rocker arm is driven by an ec-
centric machined as an integral part of the cam-
shaft. Fuel is drawn into the fuel pump on the
upward stroke of the diaphragm as the rocker arm
is moved downward by the cam eccentric against
the force of the spring. A pulsator diaphragm is
used to cushion the surging of fuel from the pump.
The diaphragm is forced downward by the spring,
during the delivery stroke of the pump and exerts
pressure on the fuel equal to the spring load as
the eccentric travels to minimum stroke. This
design provides a smooth, even flow of fuel to the
carburetor.
Most engine operating conditions do not require
full travel of the diaphragm in the fuel pump.
Whenever this condition occurs, a spring and link
arrangement keeps the rocker arm in contact at
all times with the cam eccentric but the dia-
phragm has only to displace fuel equal to engine
demand.
A fuel filter is mounted on the engine oil filler
tube bracket. It receives fuel from the pump and
filters out all dirt particles in excess of approxi-
mately .002 inch in diameter. This minimizes
flooding and possible clogging of small passages
in the carburetor. Air Conditioner equipped cars
use a fuel filter with an outlet passage that re-
turns fuel vapors to the fuel tank under high
temperature conditions, Fig. 10-3.
A carburetor air inlet baffle is installed on the
underside of the hood. This baffle lessens the
possibility of ice forming inside the venturi when
driving long distances in cool, humid weather.
This icing would restrict the required volume of
air from going into the engine, resulting in poor
power and fuel economy.
The carburetor air cleaner incorporates a re-
placeable, oil-wetted, polyurethane foam element
to remove dirt from the air before it enters the
carburetor and engine.
Certain transmission and vehicle speed condi-
tions are such that sudden release of accelerator
pedal pressure might cause the engine to returp
too quickly to idle speed, with subsequent stalling
of the engine; to prevent this stalling a vacuum-
operated throttle check is incorporated on the
throttle linkage. The unit operates by a combin-
ation of spring pressure and engine manifold
vacuum.
Air Conditioner equipped cars have a vacuum-
operated idle speed-up control attached to the
carburetor. This device is designed to increase
the engine idle RPM from 480 to 900 when the
selector is in the Neutral " N " position and the
Air Conditioner switch is "ON". This provides
adequate interior cooling and guards against
possible engine over-heating during idling.
The 1963 Cadillac engine uses either the
Rochester Model 4GC or Carter Model AFB
carburetor. These carburetors are both of the
four-barrel design, incorporating two primary and
two secondary bores.
A single exhaust system is used on all 1963
Cadillac cars. The system consists of a "Y"
exhaust pipe, muffler with aluminized cover, two-
section intermediate pipe, resonator and outlet
pipe, Fig. 10-3. These units are supported by
Vapor Return Line
Fuel Pump
Vapor Return Line
Fuel Tank Vent Pipe
Resonator
Outlet Pipe
Fig. 10-3 Exhaust and Fuel Supply Systems