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