ARMY TM 9-2815-255-24 AIR FORCE TO 38G1-95-2 MARINE CORPS TM 2815-24/4 j. Install fixture (19969) in vise (clamping on flat area) so that air inlet hole is not covered by vise.  Install a 1/4 18 NPT  fitting  in  air  inlet  of  fixture.    Connect  fitting  to  a  supply  of  clean  filtered,  compressed  air,  regulated  to  a pressure of 40 to 100 psi (275 to 689 kPa). NOTE To set roller-to-roller dimension to specification, turn leaf spring screw (25) inward (clockwise) to increase, and outward (counterclockwise) to reduce roller-to-roller dimension. k. Using   a   micrometer,   measure   roller-to-roller   dimension   (distance   between   outer   surfaces   of   opposed   cam rollers).  Dimension should be 1.9845 to 1.9875 inches (50.032 to 50.118 mm), refer to FIGURE 3-74. FIGURE 3-74.  Measuring Roller-To-Roller Dimension NOTE The   roller-to-roller   setting   provides   a   completely   accurate   maximum   fuel   adjustment   and   it should not differ from value of 95.5 to 96.5 cu mm/stroke (1564.9 to 1581.3 cm3). I. Perform a centrality check as follows.  Maximum allowable tolerance is 0.004 inch (0.102 mm). (1) After  setting  roller-to-roller  dimension,  rotate  rotor  until  one  roller  is  aligned  with  dial  indicator  plunger. Slide  indicator  inward  until  plunger  depresses  it  at  least  0.010  inch  (0.25  mm).    Lock  indicator  retaining screw zero dial indicator on high point of roller by rotating knurled dial. (2) Rotate rotor (either direction) until other roller depresses dial indicator plunger. (3) If   roller   centrality   is   beyond   specified   tolerance,   roller   and/or   shoes   can   be   interchanged.      Recheck centrality after each change and recheck roller-to-roller dimension. m. Rinse hydraulic head assembly in clean calibrating oil. n. Remove rotor assembly from fixture, ensuring shoes and rollers remain in their respective slots.  Rinse assembly in clean calibrating oil. o. Insert rotor assembly into hydraulic head. NOTE If cam ring (24, FIGURE 3-52) is installed incorrectly, pump will not be in time with engine. p. Place  cam  ring  (24)  onto  rotor  assembly  with  directional  arrow  indicating  direction  of  pump  rotation.    (Pump rotation is as viewed from drive end.) 3-103