13 Carefully remove observation windows (28 and only
Clean all parts per TM 9-254.
If cover is broken, damaged, or missing, repair is by replacement of next higher assembly.
Repair is by replacement of authorized parts as required. Refer to appendix B.
If removed, apply sealing compound (item 10,
appx C) to edges of observation windows (1 and
Install observation windows (1 and 2) in cover
(3). Remove excess sealing compound.