Legend for figure 3-22:
Cable plug connector
Screw, cap (4 reqd)
Mounting shelf, feeder
3-43. POPPET VALVES, SEAT, GASKET AND DIAPHRAGM.
Do not work on pump unless circuit breaker is OFF and electrical cable plug connector (1, fig. 3-22) is
disconnected from the feeder.
Replacement of Pump Diaphragm.
Use pin (1, fig. 3-23) to turn and remove screw (2) from end plate (3).
Remove eight hexagon capnuts (4) and washers (5); take off end plate (3) and pressure disk (6).
Use pins (7) to turn and remove screws (8) securing yoke clamps (9) to pump body (10); remove
Remove pushrods (11) by unscrewing end plate (3) and pump diaphragm (12).
Do not remove the diaphragm unless it is to be replaced.
Dry-cleaning solvent, P-D-680, used to clean parts is potentially dangerous to personnel and property.
Wear chemical resistant gloves when using solvents, and avoid repeated or prolonged skin contact. Do
not use near open flame or excessive heat. Flash point of solvent is 100 degrees F to 138 degrees F (38
degrees C to 59 degrees C).
Cleaning and Inspection.
Clean all foreign matter from components. A white coating on any part is an indication of mineral deposits.
Remove by wiping or soaking the part in muriatic acid (a 5% hydrochloric acid solution) or dry-cleaning solvent.