TM 10-3930-671-24 SECTION 5 REASSEMBLY STEP 1 Rinse rotor thoroughly in clean fuel or calibrating oil.  Place  the  rotor  on  rotor  support  and  secure  rotor support in vise. Install the delivery valve to its bore using extractor. Make sure it slides freely in its bore. NOTE Do  not  mistake  slight  interference  of  the  retractor collet  in  the  bore  for  delivery  valve  sticking.  If  the valve    is    not    secured    straight    and    tight    in    the retractor  collet,  the  collet  diameter  can  drag  in  the rotor bore. Install delivery valve spring and a new delivery valve stop to the rotor bore (Figure 5.1). Installation of a used stop can result in leakage and low output at cranking speeds. Start   the   delivery   valve   retaining   screw   into   the   bore using the hex end of the delivery valve Extractor. Tighten the screw to the specified torque. Excessive    tightening    of    this    screw    may    cause seizure  of  the  hydraulic  head  and  rotor  assembly. Insufficient    torque    may    cause    leaking    and    hard starting. FIGURE 5.1. DELIVERY VALVE REPLACEMENT Delivery valves of various retraction values are  used  for different applications. Correct part numbers are found on individual  pump  specifications.  The  letters  ’OV"  etched on the base of the rotor indicate a .001’ oversize delivery valve bore. A rotor so marked must use a .001" oversize delivery   valve.   Part   numbers   for   both   standard   and oversize valves are listed on individual pump specifications.  The  oversize  valve  is  also  identified  by blackening on both ends and in the groove on the delivery valve shank. STEP  2  Remove  the  rotor  from  the  holding  fixture  and submerge  it  in  clean  calibrating  oil.  Install  the  pumping plungers   and   check   them   for   freedom   of   movement. Assemble the leaf spring, leaf spring adjusting screw and shim (if used) to the rotor (Figure 5.2). FIGURE 5.2. PLUNGER REPLACEMENT Since  the  plungers  are  positioned  centrally  in  the  bore during operation and their travel is extremely short, wear of plungers is negligible. Replacement, however, may be made in instances where rust or damage in handling has occurred.  Plungers  of  any  given  nominal  diameter  are graded in four select fit sizes: A, B, C, and D. The rotor is etched  with  the  letter  indicating  bore  size.  This  mark  is found on the base of the rotor.  If plunger replacement is required, check the size designation on the rotor and use the  plunger  of  corresponding  part  number  as  indicated on    individual    specifications.    For    example:    A    .330" diameter  plunger  bears  basic  part  No.  11076  and  the graded sizes, A through D, bear part No. 11077 through 11080,   respectively.      The   replacement   plungers   for   a .330’   diameter   plunger   pump   with   a   rotor   marked   C" would   be   part   No.   11079.      Always   refer   to   correct individual specifications for part numbers. NOTE A  limited  number  of  pumps  will  have  a  “-2”  etched on  the  rotor  following  the  letter  grading  code.  This mark indicates a .002" (.05rm) oversize plunger bore. Replacement  should  be  ordered  according  to  the oversize     plunger     group     shown     on     individual specifications. F-235