COOLING SYSTEM precharge the cooling system to the recommended concentration.      The   precharge   (larger)   coolant   filter   should only be used to precharge the cooling system on a new engine or  when  the  coolant  is  replaced.    The  continued  use  of  the precharge  element  could  result  in  plugging  and  overheating problems. The normal service element is  used  to  replace  the  precharge element    after    the    first    19    000    km    or    12,    000    miles. Subsequent replacements of the normal service element after 16   000-19   000   km   or   10,   000-12,   000   mile   intervals   will maintain  the  required  concentration.    Servicing  too  often  may result in the formation of a white deposit in the system. Unlike the old borate and chromate water filters, the new water filters  must  be  used  only  after  the  cooling  system  has,  been thoroughly    drained    and    chemically    flushed    with    inhibited hydrochloric acid or inhibited oxalic acid. Failure to chemically flush, prior to using the new water filters, may result in plugged radiator  and  heater  cores  or  even  solder  deterioration.    The chemical   in   the   new   water   filters   will   loosen   any   cooling system scale. Systems Without Coolant Filters Vehicles    without    a    coolant    filter    must    have    the    coolant inhibitors  replenished  by  adding  IH  cooling  conditioner.  The conditioner     should     be     added     as     recommended     in     the respective Operator’s Manuals. NOTE--  A  complete  drain,  flush  and  refill  with  water  and conditioner, or IH anti-freeze and coolant is recommended once   a   year.      This   Includes   all   vehicles   regardless   of yearly mileage. If  the  cooling  system  has  been  permitted  to  become  rusty  or dirty,  use  IH  cooling  system  cleaner  and  neutralizer  carefully, following cleaning recommendations on the container. Coolant Testing for Inhibitor Strength Coolant  should  be  checked  for  reserve  alkalinity,  using  test strips   available   from   various   sources,   at   each   oil   change. Indication   of   a   low   alkalinity   condition   requires   adding   IH cooling     conditioner,     changing     cooling     filter     or     changing contaminated coolant. DRAINING THE COOLING SYSTEM When the cooling system of a vehicle is drained, some coolant is  likely  to  be  retained  in  the  pockets  of  the  cooling  system. This is especially true in  engines  equipped  with  oil  coolers  or heat  exchangers   having   a   tube   bundle.      If   only   water   with cooling conditioner is used and these engines are drained and then  exposed  to  freezing  temperatures,  the  water  conditioner will freeze and possibly rupture one or more of the tubes. The resulting  leak  will  be  difficult  to  locate  and  could  eventually damage the engine by mixing the coolant with the engine oil. To avoid damage, take one of the following precautions when draining for shipment or storage in freezing temperature: 1. Fill    the    cooling    system    with    anti-freeze    solution, operate engine until the thermostat opens or until circulation is observed in the radiator circuit, then drain. 2. If conditioned water is used, drain  the  engine.    Then blow    out    the    residual    solution    in    the    cooler    tubes    with compressed air through one of the drain cocks or plugs on the cooler. CLEANING THE COOLING SYSTEM Once   a   year   the   cooling   system   should   be   drained   and thoroughly flushed. Unless    the    cooling    system    is    treated    with    a    corrosion preventative, rust and scale will eventually clog up passages in the radiator and water jackets.  This condition is aggravated in some  localities  by  formation  of  insoluble  salts  from  the  water used. IH  cleaning  solutions  are  available,  which  have  proven  very successful  in  removing  accumulation  of  rust,  scale,    sludge and  grease.    This  solution  should  be  used  according  to  the recommendation on the container. CAUTION - DO NOT USE CHEMICAL MIXTURES TO STOP RADIATOR LEAKS EXCEPT IN ANY EMERGENCY.  NEVER USE SUCH SOLUTIONS INSTEAD OF NEEDED RADIATOR REPAIR. When  draining  the  cooling  solution,  disconnect  the  radiator outlet   hose,   as   large   particles   of   sediment   will   not   pass through the drain. WARNING - USE ONLY THE FOLLOWING PROCEDURE TO REMOVE THE PRESSURE-TYPE CAP FROM THE RADIATOR.      ALWAYS   ALLOW   THE   ENGINE   TO   COOL FIRST.      WRAP   A   THICK,   HEAVY   CLOTH   AROUND   THE CAP.  PUSH DOWN, LOOSEN CAP SLOWLY TO ITS FIRST NOTCH POSITION; THEN PAUSE A  MOMENT.    THIS  WILL AVOID POSSIBLE SCALDING BY HOT WATER OR STEAM. CONTINUE TO TURN CAP TO THE LEFT AND REMOVE. CAUTION  -  IF  THE  COOLANT  SHOULD  GET  EXTREMELY LOW   AND   THE   ENGINE   VERY   HOT,   LET   THE   ENGINE COOL     FOR     APPROXIMATELY     15     MINUTES     BEFORE ADDING COOLANT.  THEN, WITH THE ENGINE RUNNING, ADD  COOLANT  SLOWLY.    ADDING  COLD  WATER  TO  A HOT   ENGINE   MAY   CRACK   THE   CYLINDER   HEAD   OR CRANKCASE. 1. Coolant shut-off cocks to heaters and other accessories   should   be   open   to   allow   complete   circulation during  cleaning,  flushing  and  draining.    Run  the  engine  with the  radiator  covered  if  necessary,  until  temperature  is  up  to operating range of 72-84°C CTS-4181 Page 8