CAUTION Assemble  the  fuel  injector  in  a  clean,  well  lighted  work area isolated from the rest of the shop. NOTE Before   assembling   injector,   all   injector   parts   shall   be dipped  in   engine   fuel   per   Military   Specification   MIL-J- 5624 or Federal Specification VV-F-800. NOTE Make  sure  that  the  guide  pins  on  intermediate  disc  (5) bottom  are  inserted  properly  into  matching  holes  on  top of nozzle (6). (1)   Install nozzle (6), intermediate disc (5), pres-sure spindle     (4),     and     pressure     spring     (3)     and appropriate number of shims (2) in holder (7). (2)   Screw  retainer  nut   (1)   onto   nozzle   holder   (7). Tighten nut (1) to 63 lbs ft (85 Nm) torque. (3)   To  test  the  fuel  injector  assembly,  proceed  as follows: NOTE Use  clean  filtered  diesel  fuel,  per  Military  Specification MIL-J-5624 or Federal Specification VV-F-800, in nozzle tester. (a) Loosely  connect  injector  to  be  tested to nozzle tester (Table 2-1) using test line listed in Table 2-1.  Pump nozzle testers  handle  several  times  to  flush air     from     test     line.          Tighten     all connections. WARNING Keep    hands    away    from    nozzle    spray.        Spray    can puncture   the   skin   allowing   test   oil   to   enter   the   blood stream.    Consult  a  physician  at  once  if  spray  punctures the skin. (b) Close valve to bypass pressure gauge. (c) Pump  nozzle  testers   handle   up   and down   quickly   (approximately   six   to eight times a second).  Fuel should spray from injector nozzle tip in an atomized  mist  (see  Figure  6-27)  and the  nozzle  should  emit  a  sharp  high- pitched chatter. (d) If nozzle does not chatter, flush nozzle by     pumping     tester     handle     rapidly. Repeat step c. (e) Pump the nozzle testers handle several   times   to   flush   air   from   the nozzle.    Open  pressure  gauge  valve. Slowly pump tester handle while observing   pressure    gauge.        Nozzle should  open  at  2,  600  +  120  -  0  psig (17, 927 + 827- O0 KPa). NOTE Do  not  wipe  the  nozzle  tip  with  the  fingers  as  this  will tend to draw the fuel present in the sac hole through the orifices  and  falsely  indi-cate  a  leak  and  rejection  of  a good  valve.    Hold  a  wiper  lightly  against  the  tip  of  the valve. (f) Bleed  off  pressure  until  nozzle  valve seats.    Using  a  lint  free  cloth,  wipe nozzle tip dry. Figure 6-27.  Fuel Injector Spray Pattern 6-62