TM5-6115-593-34 NAVFAC P-8-631-34 TO-35C2-3-463-2 screws,   hose   connections,   pipe   plugs, and filter screen cap. (19)  Housing Porosity Check. (a)   Fill fuel pump with clean fuel or test oil. (b)   Remove   suction   fitting   at   gear   pump and   install   fittings   so   an   air   pressure hose may be attached. (c)   Air  supply.hose  line  must  be  equipped with  a  valve  and  gauge  to  control  air pressure at a maximum of 20 psi. (d)   Apply 20 psi air pressure; do not exceed 20 psi or damage to seals may result. (e)   Pour  fuel  oil  over  pump  and  examine carefully     for     air     bubbles,     indicating leaks.  Alternately wipe pump or specific area   dry   and   check   for   wet   seepage. Do not use this check for seals. (20)  Gear Pump Test. (a)   Use  a  fuel  pump  build  up  with  only  the parts  required  to  drive  the  gear  pump, minimum of pump body, with tachometer drive and a complete mainshaft cover assembly.  If desired, a complete  fuel  pump  can  be  used  if  the governor    plunger    and    weight    assist plunger and spring assembly are removed and pump housing is filled with fuel;    this    will    prevent    any    possible damage to governor plunger or governor  barrel.    Gear  pump  may  be mounted    directly    to    test    stand    with adapter bracket. (b)   Install    gear    pump    block    plate,    with gasket    on    each    side,    between    gear pump and fuel pump body. (c)   Remove  fuel  pump  damper  from  gear pump   and   connect   copper   line   from orifice block to gear pump pressure tap. (d)   Connect   the   fuel   suction   line   to   the suction  side  of  the  gear  pump.    Run  a line from the gear pump bleed connection to the fuel supply tank. (e)   Shut    off    the    fuel    manifold    pressure gauge   to   prevent   damage   from   over pressure. (f)    The  valve  in  the  suction  line  and  the valve  controlling  the  main  flow  orifice are  to  be  fully  open.    All  other  valves must  be  completely  closed.    With  the valves    in    this    position,    fuel    will    be routed through the manifold orifice. (g)   Start the pump drive and run the pump at   400   to   450   rpm.      The   gear   pump must  pick  up  at  this  speed  without  the aid  of  priming.    Any  gear  pump  which fails  to  pick  up  fuel  must  be  rebuilt  or replaced  in  accordance  with  paragraph 13-10f. b. Instructions for the Fuel Pump Test Stand.  The fuel  pump  test  stand,  figure  13-26,  is  required for  accurate  testing  and  calibration  of  the  feel injection  pump.    Pump  speeds  may  be  varied continuously  from  475  to  4750  rpm.    Correct calibration  of  the  fuel  injection  pump  is  one  of the   most   important   procedures   to   satisfactory engine operation. (1)   Test Oil.  The fuel pump test stand must be filled   with   clean   test   oil   No.   99011-68   or equivalent. 13-44