TM 5-3895-383-24
Starting Aids
The use of a starting aid is a conventional method of
assistance for cold starts in low temperature conditions. A
variety of starting aids are available for Caterpillar engines.
Follow the recommendations that are provided by the
manufacturer of the starting aid. Information about the use of
staring aids is included in the Operation and Maintenance
Manual for your machine.
Engine Coolant Heaters
These heaters heat the engine coolant. The heated coolant
flows through the cylinder block. The flow of heated coolant
keeps the engine warm. A warm engine is easier to start in
cold weather. Most coolant heaters use electrical power. A
source of electricity is necessary for this type of heater. Other
heaters that burn fuel are available as a source of heat. These
heaters may be used in place of the electrical heaters.
With either type of heater, staring aids and/or fuels with higher
cetane numbers are less important because the engine is
warm. Problems with fuel cloud point can cause the plugging
of fuel filters. Problems with fuel cloud point cannot be
corrected by engine coolant heaters. This is especially true for
machines that allow the fuel filter to be cooled by air flow
during operation.
Fuel Heaters
The fuel cloud point is related to problems with fuel filters. The
heater heats the fuel above the cloud point before the fuel
enters the fuel filter. This prevents wax from blocking the filter.
Fuel can flow through pumps and lines at temperatures below
the cloud point. The cloud point is often above the pour point
of a fuel. While the fuel can flow through these lines, the wax
in the fuel can still plug the fuel filter.
In some engine installations, small modifications can prevent
problems that are caused by the cloud point. One of the
following changes can prevent problems in many conditions: a
change in the location of fuel filters and/or supply lines and the
addition of insulation. In extreme temperatures, heating of the
fuel may be required to prevent the filters from plugging. There
are several types of fuel heaters that are available. The
heaters use either engine coolant or exhaust gas as a heat
source. Most of these systems will prevent all filter problems
without the use of de-icers. These systems may be ineffective
when the fuel contains a large amount of dirt or of water. Use
of a fuel heater can help eliminate some cold weather
problems. A fuel heater should be installed so that the fuel is
heated before flowing into the fuel filter.
NOTE:
Only use fuel heaters that are controlled by
thermostats or use fuel heaters that are self-
regulated. Do not use fuel heaters in warm
temperatures.
Select a fuel heater that is mechanically simple, yet adequate
for the application. The fuel heater should also prevent
overheating of the fuel. Disconnect the fuel heater or
deactivate the fuel heater in warm weather. An unacceptable
loss of fuel viscosity and engine power will occur if the fuel
supply temperature is allowed to become too hot.
For additional information on fuel heaters, see your Caterpillar
dealer.
De-lcers
De-icers lower the freezing point of the moisture in the fuel.
De-icers are not generally needed when fuel heaters are used.
If you experience trouble, consult your fuel supplier for
recommendations of a compatible commercial de-icer.
Characteristics of Diesel Fuel and Modification to
Characteristics of Diesel Fuel
The primary characteristics that affect engine operation and
performance
in
cold
temperatures
are
the
following
characteristics: Lubricity, Viscosity, Cetane Number, Cloud
Point, Pour Point, and Moisture Content. Refer to Special
Publication, SEBD0717 "Diesel Fuels and Your Engine" for
information about the following fuel properties: ignition quality,
gravity (density), viscosity, cloud point, pour point, and sulfur
content.
Lubricity and Low Sulfur Fuel
NOTE:
The fuel lubricity is important. You should
consider the fuel's lubricity whenever you operate
the equipment in arctic weather. Also, you should
consider the fuel's lubricity whenever you use
fuels that are lower in viscosity. There are many
aftermarket additives that are available to treat
fuel. If the fuel's lubricity is an issue, consult your
fuel
supplier
for
proper
recommendations
regarding fuel additives.
Maintenance Section
Fuel Specifications
1-33
