ARMY TM 9-2815-256-24
AIR FORCE TO 38G1-96-2
MARINE CORPS TM 2815-24/5
FIGURE 3-91. Measuring Roller-To-Roller Dimension
Perform a centrality check as follows. Maximum allowable tolerance is 0.004 inch (0.102 mm).
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.
Rotate rotor (either direction) until other roller depresses dial indicator plunger.
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.
Rinse hydraulic head assembly in clean calibrating oil.
Rest unit on weight retainer (33, FIGURE 3-73).
If cam ring (24) is installed incorrectly, pump will not be in time with engine.
Place cam ring (24) onto rotor assembly with directional arrow indicating direction of pump rotation. (Pump
rotation is as viewed from drive end.)
Place hydraulic head on rotor.
Position two rotor retainers (23) on head and rotor with cutout portions meeting over spring pin hole in hydraulic
Position liner locating ring (22) over rotor retainers (23) and bottom it against head. Position split in ring 90
degrees from split in retainers.
Preformed packing (16) has an oval cross section and can be identified by rolling it between fingers.
Install new Preformed packing (16) in groove on hydraulic head (17). Be sure to push packing all the way into its
Install liner (15) so slot is lined up with hole in which regulator assembly roll pin (12) enters.