Maintenance Recommendations Cooling CAUTION Never  add  coolant  to  an  overheated  engine;  allow the   engine   to   cool   first.   Check   specific   gravity   of antifreeze   solution   frequently   in   cold   weather   to assure adequate  protection. Coolant    should    be    drained    and    replaced    "Every 2000     Service     Meter     Units."     With     additions     of Caterpillar Cooling System Conditioner or the use  of Caterpillar Coolant Conditioner Elements as recommended, the drain period can be extended  to "Every 4000 Service Meter Units". All  water  is  corrosive  at  engine  operating  tempera ture.    The  cooling  system  should  be  protected  with conditioner  at  all  times  regardless  of  concentration of antifreeze. When   changing   coolant   or   on   initial   fill,   use   a   3 percent    solution    of     Caterpillar     Cooling     System Conditioner.   This  can  be  accomplished  with  .5  liter of  conditioner  for  every  15  liters  of  cooling  system capacity     (1     pint     for     every     4     gallons).          This concentration    can    be    maintained    by    conditioner additions  "Every  250  Service  Meter  Units."  Add  .5 liter   of   conditioner   for   every   76   liters   of   cooling system capacity (1 pint for every 20 gallons). Most  systems  will  require  2  liters  (2  quarts)  of  con- ditioner at initial fill and .50 liters (1 pint) "Every  250 Service Meter Units." Do  not  use  Caterpillar  Cooling  System  Conditioner with  Dowtherm  209  Full-Fill  coolant.    Follow  the  re commendations   provided   with   the   Dowtherm   209 Full-Fill coolant. If  the  engine  is  to  be  stored  or  used  in  an  area    with below  freezing  temperatures,  the  cooling    system  must be protected to the lowest expected ambient temperature. Operate with a thermostat in the cooling system  all year- round.   Problems  can  arise  without  a  ther  mostat  in  the cooling system. Use clean water that is low in scale forming minerals, not softened water. Always    recheck    the    coolant    level    when    the    engine reaches  normal  operating  temperature.    Add  coolant  as necessary to bring up to proper level. Filling  faster  than  19  liters  (5  U.S.    gallons)  per    minute can cause air pockets in the cooling  system. Premix the antifreeze solution to provide protection to the lowest expected ambient temperature. Electrical System CAUTION When  using  jumper  cables  to  start  the  engine,  be sure  to  connect  in  parallel:    POSITIVE  (+)  to  POSI TIVE (+) and NEGATIVE (-) to NEGATIVE (-). When  using  external  electrical  source   to   start   the engine,  turn  the  disconnect  switch  off  and  remove the key before attaching jumper cables. Never  use  both  liquid  cooling  system  condition  er  and coolant conditioner element at the same  time. When   permanent   antifreeze   and   water   solutions   are used   in   the   cooling   system,   the   solution   should   be drained and replaced "Every 2000 Service Meter Units". When cooling system conditioner additions are made "Every 250 Service Meter Units" as recommended, this change period can be extended to "Every 4000 Service Meter Units or Two Years." Scheduled Oil Sampling Use Scheduled Oil Sampling to monitor engine  condition and maintenance requirements.  Each oil  sample should be taken when the oil is hot and  well mixed to insure a sample    which    is    representative    of    the    oil    in    the compartment.  Samples  should be taken at each engine oil  change.    Consult  your  authorized  Caterpillar  engine dealer    for        complete    information    and    assistance    in establish  ing  a  scheduled  oil  sampling  program  for  your engine. 21