TM 55-1930-209-14&P-19 Table 3.3.  Preventive Maintenance Checks and Services for ROWPU System (Continued) B - Before D - Daily Q -  Quarterly D - During W - Weekly S -  Semiannually A - After M - Monthly A -  Annually INTERVAL ITEM PROCEDURES EQUIPMENT ITEM TO BE CHECK FOR AND HAVE IS NOT READY/ NO. INSPECTED REPAIRED OR ADJUSTED AVAILABLE IF B   D   A   D  W  M   Q   S   A AS NECESSARY 4)  Use drum lifter and bridge crane with 2-ton hoist to obtain new drum.  Posi- tion and secure drum in rack 5)  Install section hose in drum through hole in large lung.  Foot valve should be just above the drum bottom. 6)  Connect other end of suction hose to chemical metering pump. 7)  Insert breather hose into smaller lung in drum.  Make sure hose does not siphon chemical onto the deck. * d.  Check for chemical seepage around Class Ill leaks. head disk.  If seepage occurs replace pump diaphragm as follows: 1)  Place pump stroke length knob at 100 percent. 2)  Remove four screws and flatwashers holding dosing head to pump. Remove dosing head. 3)  Place pump stroke length knob at 0 percent.  Remove pump diaphragm by turning counterclockwise.  The head disc will also fall free. 4)  Install replacement diaphragm by holding head disc in position (drain slot on inside) and turning diaphragm clockwise onto plunger shaft end. Grasp perimeter of diaphragm and hand tighten. 5)  Place pump stroke length knob at 100 percent.  Rotate head disc until marker hole is up and drain slot is down.  Align four screw holes with motor housing holes. 6)  Install dosing head with arrow ori- ented up.  Secure dosing head with four screws and flatwashers.  Tighten screws evenly. Change 1      3-8