Section III. OPERATOR MAINTENANCE PROCEDURES

TM 10-4330-237-13&P Section III. OPERATOR MAINTENANCE PROCEDURES 3.2 REPLACE UNISEX COUPLING FACE SEAL/DUST CAP SEAL. This procedure applies to both 2-inch and 3-inch unisex couplings. The seal in each adjacent coupling face and dust cap are identical and may be interchanged as a temporary repair. This task consists of: a. Removal b. Installation INITIAL SET-UP: Tools: Materials/Parts Required: None Rag, Wiping (Appendix F, Section II, Item 7) General Safety Requirements: Equipment Condition: AAFARS not in operation WARNING · Fuels are toxic and flammable. Do not get on person or clothing. Do not use near open flame. Area should be well ventilated. · Fuel is flammable. Do not smoke. NOTE The face plate and dust cap of liquid fuel filter-separator unisex couplings employ a U-ring type seal which is designed to seat with pressure. The seal is slightly higher than the groove it sits in, so that the top protrudes above the surface. Pressurized fluid enters beneath this protrusion and expands the seal against the bottom of the seal groove, and against the corresponding seal in the dust cap or other face place. Special care must be taken during installation to ensure the seal is fully seated in the groove. If it is not, pressurized fluid will be forced under the seal and the coupling will leak. a. Removal. (Figure 3-1) 1. Remove face seal (1) by hand. b. Installation. (Figure 3-1) 1. Wipe seal groove clean. 2. Press seal in groove with a smoothing motion of fingertips. Note that when fully seated, the outer lip of the seal protrudes slightly above the surface. Ensure the seal is not twisted or kinked. 3-2