Section X. WATER PUMP AND FAN 14-56.   General. a.  The  water  pump  is  a  centrifugal  type  pump  that circulates   coolant   through   the   engine   and   radiator. The  pump  is  mounted  on  the  front  of  the  cylinder block  and  is  belt  driven  from  the  crankshaft  pulley. Coolant  is  drawn  through  the  inlet  opening  by  the pump  impeller  and  forced  through  the  outlet  in  the backside  of  the  volute  and  into  the  cylinder  block,  and the  lube  oil  cooler. b.  The  water  pump  shaft  and  bearing  assembly does  not  require  lubrication  because  the  bearing  is  of the   sealed-for-life   type.   A   water   slinger   on   the pulley  end  of  the  shaft  slings  any  coolant  which  might seep  past  the  seal  assembly  out  the  cored  opening  in the  pump  body,  thus  preventing  coolant  from  coming in  contact  with  the  shaft  bearing.  The  shaft  and bearing  assembly  is  secured  in  the  pump  body  by  a press   fit   and   a   retaining   snap   ring.   The   seal   be- tween  the  impeller  and  pump  body  is  of  the  packless type.   The   seal   assembly   is   spring   loaded   and   is pressed  into  the  pump  body  forming  a  leakproof  seal at  this  point, c.  The  fan  is  located  behind  the  radiator  on  the front  of  the  engine. The  fan  is  belt  driven  from  the engine  and  draws  cooling  air  through  the  louvered panel  at  the  rear  of  the  unit  and  exhausts  it  through the  radiator  core,  shutter  and  grille. 14-57.   Removal   and   Disassembly. a.   Water   Pump   Removal. Refer   to   Operator   and   Organizational   Maintenance Manual. b.   Fan   Removal. Refer   to   Operator   and   Organizational   Maintenance Manual. c.  Water  Pump  Disassembly. (1)  Place  water  pump  in  a  press  and  remove pulley hub. (2)  See  figure  14-27  and  disassemble  water pump   as   illustrated. (3)  Place  water  pump  assembly  in  position  on a   press,   impeller   end   up.   Make   certain   the   pump rests  on  back  of  pump  body  and  not  on  the  water  inlet or  drain  hole. Press  end  of  shaft  until  shaft  and bearing  assembly  is  out  of  the  pump  body.  Remove impeller  from  the  pump  body. (4)  Drive  out  seal  assembly  with  a  drift  pin  or rod  and  a  hammer.  , 14-58.   Inspection   and   Repair. a.  Check  condition  Of  pump  shalt  and  bearing assembly   by   rotating   the   bearing.   If   the   bearing Figure   14-27.   Water   Pump is  binding,  running  dry  from  lack  of  lubricant,  or feels  rough,  the  shaft  and  bearing  assembly  must  be replaced.   If   the   slinger   is   damaged,   it   must   be replaced. CAUTION Do  not  clean  shaft  and  bearing  assembly in   cleaning   solvent   because   the   lubricant will  be  washed  from  the  bearing. b.   Check   condition   of   the   ceramic   seal   insert bonded  to  the  pump  impeller.  If  it  is  rough,  cracked, or  chipped,  replace  the  impeller. c.  Thoroughly  clean  pump  body  with  cleaning solvent,   Federal   Specification   P-D-680. d.  Check  condition  of  bearing  bore  in  the  body. Replace  pump  body  if  cracks  are  evident. e.   Replace   the   water   pump   seal   assembly. 14-59.   Reassembly   and   Installation. a.   Pump   Reassembly. (1)  Position  pump  body  on  press,  impeller  end up.   Position   seal   assembly   in   the   pump   body.   Place seal  installer  tool  on  the  seal  and  press  seal  into pump  body,  making  certain  the  carbon  sealing  sur- face  is  not  damaged. CAUTION Face  of  seal  assembly  must  be  free  of oil,   grease,   and   fingerprints   before   seal assembly   is   installed. (2)  Position  pump  body  on  press,  bearing  bore up.   Start   shaft   and   bearing   assembly   into   bore, slinger   end   of   shaft   down.   Press   shaft   until   bearing seats  on  shoulder  in  the  pump  body.  The  slinger must  be  1-15/16  inches  from  the  end  of  the  shaft Change   7   14-61