TM 5-1940-321-13&P
( 12 ) Remove the disk-shaped neoprene valve cap gasket Figure 5-4, item 2 from
the metal valve cap. Clean the gasket by rubbing it between your fingers and
thumb to remove any dirt. Inspect the diaphragm for cracks or other indications
of deteriorations. The valve cap gasket becomes grooved after a period of
service. If it is not damaged and only one side of the gasket has circular
grooves, the gasket can be reinstalled with the ungrooved side out.
CAUTION
The diaphragm is designed to pass a small amount of air for pressure
readings. The valve cap gasket is the final air seal and must be airtight.
Failure to secure cap will cause the IAB to lose air and compromise the
safety of personnel.
( 13 ) Clean the metal valve insert body and metal valve cap in toluene. Scrub both
parts with a brush and rinse in toluene. It is important that the threads are very
clean. No lint from the towel should remain on the threads.
( 14 ) Reinstall the cleaned valve cap gasket or a new gasket in the valve cap. Used
gaskets should be installed with the ungrooved side facing outward.
( 15 ) Reinstall the cleaned diaphragm or a new diaphragm in the metal valve insert.
Insert the stem of the diaphragm into the valve insert by hand as shown in
figure 5-8. Then pull it into position using needle nose pliers to grip the stem as
shown in figure 5-9.
5-20
