TM 5-1940-321-13&P
( 2 ) Perform the leak test described in chapter 6, paragraph 6-3 to determine the
exact point at which the CO2 inlet valve is leaking and the appropriate
corrective action required. Figures 7-1 through 7-5 show the specific cause of
different types of valve leaks. Table 7-1 references corrective maintenance
procedures by valve type.
Figure 7-6. Foot Pump Components.
7-13. REPAIRING FOOT PUMP (Figure 7-6). The foot pump is repaired when it does not pump air or
when a leak reduces the amount of air pumped. The most common causes of failure are leaks in the
fabric bellows and malfunctioning valves. The foot pump is repaired by replacing components.
a. Fault Location. Unit personnel perform foot pump troubleshooting. Troubleshooting the foot
pump is accomplished by operating it and observing airflow. If the foot pump bellows does not return to
the extended position, the internal spring is misaligned or broken, if the foot pump operates but does
pump air, inspect the valves installed in the ports marked INFLATION and DEFLATION. When functioning
properly, these valve allow air to glow in only one direction. The valve installed in the DEFLATION port
allows air to flow into, but not out of the pump. The valve installed in the INFLATION port allows air to flow
out, but not into the pump. If either of the valves does not close completely, the pump will not function
properly. Operate the pump and check for proper operation of the valves. Test the valves one at a time.
Operate the pump with the hose inserted in the INFLATION port and then with the hose inserted in the
DEFLATION port. If the pump operates in one mode but not the other, one of the valves is not
functioning. Defective valves are replaced. Check for leaks in the fabric sleeve or under the collar clamps.
The air hose may be leaking. Worn or damaged air hose tips may be replaced. A collar clamp that is not
tight may cause air leaks.
7-10