TM 10-3930-671-24 Coolant Level Checking Coolant Do not remove the radiator cap when the radiator is hot. Steam of hot coolant from the radiator can cause severe burns. Never remove the radiator cap while the engine is running.  Stop  the  engine  and  wait  until  it  has  cooled. Remove  the  radiator  cap  only  with  engine  stopped  and when engine is cold. NOTE For maximum cooling efficiency, always keep the cooling system   filled   with   the   recommended   coolant   mixture, year around at all ambient temperatures. The cooling system is initially filled with a factory-installed solution of 50% water and 50% permanent-type antifreeze  containing  rust  and  corrosion  inhibitors.  You should leave it in year around. Plain water may be used only  in  an  emergency,  but  replace  it  with  the  specified coolant   as   soon   as   possible   to   avoid   damage   to   the system or engine. With only water in the system, do not let  the  engine  run  hot.  DO  NOT  USE  ALCOHOL  OR METHANOL ANTIFREEZE. Use    of    high-quality    antifreeze    having    a    low-silicate additive  content  is  strongly  recommended.  Low-silicate antifreeze is available for heavy-duty use. Refer   to   Section   2.1,   Service   Specifications,   Cooling System. NOTE Fork   lift   truck   applications   require   also   checking   the coolant  level  directly  in  the  radiator.  Lift  truck  radiators will  plugup  and  overheat,  which  will  force  coolant  into overflow reservoir and on out at the cap. This results in a low   coolant   level   which   exposes   the   transmission   oil cooler causing engine/transaxle overheating. 1. The  coolant  level  should  be  at  the  "Cold  level" line  on  coolant  recovery  bottle  when  engine  is cold. 2. Coolant   level   in   the   radiator   should   also   be checked at least once a day (or every 8 hours of operation)  to  make  sure  radiator  is  100%  full  at all times. 3. The correct FULL level is 0.5-0.75 in (13-20 mm) below bottom edge of filler neck opening. General Procedures NOTE If coolant has to be added more than once a month or if you  have  to  add  more  than  one  quart  at  a  time,  check the  cooling  system  for  leaks,  or  for  other  reasons,  e.g., cooling system overheating. See below. NOTE If   the   condition   of   the   used   coolant   indicates   severe contamination, rust deposits, scale or oil in the system, it may be necessary to clean and flush cooling system with a commercial cleaner. 1. If  level  is  low,  add  a  50/50  mixture  of  specified coolant and water to the correct fill level. 2. Inspect the coolant condition. Look for excessive contamination, rust, oiliness, and gummy deposits  (see  discussion  under  Engine  Coolant Change    below)    in    the    coolant    solution.    The coolant should have a clean appearance. 3. Check  the  PM  time  interval  for  need  to  change (drain and replace) coolant. 4. Check condition of radiator cap upper and lower seals    (with    overflow    reservoir,    cap    has    two seals)  and  radiator  filler  neck  for  damage.  Be sure they are clean. Replace cap, as necessary. Check overflow hose for clogging and damage. 5. If  the  cooling  system  requires  the  addition  of  a large   quantity   of   coolant,   and   the   engine   has been overheating: a) Inspect   radiator   for   blockage   of   air   flow through the fins. Air clean the radiator. b) Check    fan    belt    and    cooling    fan    drive control (as applicable). c) Check   and   be   sure   fan   is   not   installed backwards (a common problem). d) Check   engine   oil   to   see   if   it   contains coolant. e) Pressure  test  the  radiator  cap.  Replace  if faulty. f) Pressure    test    the    radiator    and    cooling system.  Repair any leaks or blockage. g) Test   the   engine   thermostat.   Replace   as needed. It   is   recommended   to   drain   and   replace   the   engine coolant every 2000 hours, or once a year. Refer to Section 4.8, Cooling System. Engine Oil Level Check NOTE It  is  normal  to  add  some  oil  between  oil  changes.  Keep the   oil   level   above   the   ADD   mark   on   the   dipstick   by adding  oil  as   required.   DO   NOT   OVERFILL.   Use   the correct oil as specified in Section 2.1, Service Specifications. 1. Check    the    engine    oil    level    every    8    hours according  to  engine  oil  dipstick  and  procedures specified for your engine model as further noted below. 2. Pull  the  dipstick  out,  wipe  it  clean  with  a  clean wiper,  and  reinsert  it  fully  into  the  dipstick  tube. Remove the dipstick and check the oil level. 3. Check the PM time interval (operating hours), or the condition of the oil to determine if it needs to be changed. F-50