SkyTrak 8042 Service Manual - Manual (Page 389)

Engine: Cummins QSB4.5T
7B.22 Model 8042, 10042, 10054 Legacy Rev. 10/03
7B.8 FUEL SYSTEM
The fuel system includes a fuel tank (1), fuel level sender
with gasket (2), instrument cluster gauge (not shown),
fuel strainer (3), fuel lift pump (4), fuel filter (5), fuel supply
hose (6) and fuel return line (7).
The threaded fuel filler (8) has a fuel cap (9) and permits
entry of diesel fuel into the tank.
The fuel level sender (2) and instrument cluster gauge
are described in Section 9.14.15, “Fuel Level Indicator
and Fuel Level Sender.”
A fuel supply hose (6) carries fuel from the tank (1) to the
fuel lift pump (4) and then under pressure to the fuel filter
(5). Filtered fuel is directed to the fuel injection pump and
to the individual fuel injectors. Surplus fuel at the fuel
injector pump is returned to the tank via the fuel return
line (7).
7B.8.1 Diesel Fuel
Fuel represents a major portion of vehicle operating costs
and therefore must be used efficiently. ALWAYS use a
premium brand of high-quality, clean diesel fuel. Low
cost, inferior fuel can lead to poor performance and
expensive engine repair.
Note: Use only diesel fuel designed for diesel engines.
Some heating fuels contain harmful chemicals that can
seriously affect engine efficiency and performance.
Due to the precise tolerances of diesel injection systems,
keep the fuel clean and free of dirt and water. Dirt and
water in the fuel system can cause severe damage to
both the injection pump and the injection nozzles. The
preferred fuel is ASTM #2 diesel fuel with a minimum
Cetane rating of 40. #2 diesel fuel gives the best fuel
economy and performance under most operating
conditions. Fuels with Cetane ratings higher than 40 may
be needed in higher altitudes or extremely low ambient
temperatures to prevent misfiring and excessive smoke.
• When operating at temperatures above 32° F
(0° C), use standard #2 diesel fuel.
• When operating at temperatures below 32° F
(0° C), use a blend of #1 & #2 diesel fuels,
most commonly known as “winterized” #2
diesel.
IMPORTANT: #1 diesel fuel may be used, however, fuel
economy will be reduced.
Use a low-sulfur content fuel with a cloud point (the
temperature at which wax crystals form in diesel fuel) at
least 10° below the lowest expected fuel temperature.
The viscosity of the fuel must be kept above 1.3
centistrokes to provide adequate fuel system lubrication.
Note: When using diesel fuel with a sulfur content below
1.3 percent, the filter change interval must be reduced by
75 hours. The use of fuel with a sulfur content above
1.3 percent is not recommended.
WARNING:
Engine fuel is flammable
and can cause a fire or an explosion. Keep
sparks and open flames away from the vehicle
and DO NOT use smoking materials while
refueling.
WARNING:
DO NOT mix gasoline or
alcohol with diesel fuel. The mixture can cause
an explosion.