Note.—The first and most important precaution to be observed in assembling guns and carriages is that all parts must be clean. Where dismounting but not assembling operation is described, assembling is approximately the reverse of dismounting. I. To remove recoil cylinder. II. To disassemble recoil cylinder. III. To assemble recoil cylinder. IV. To dismount gun. V. To remove counter-recoil spring. VI. To remove breechblock. VII. To replace piston rod, gland pkg. VIII. To remove wheel. IX. To remove shields. X. To remove spring cylinder. XI. To remove sight. XII. To remove rocker and rocker arms. XIII. To remove top carriage. XIV. To remove equalizing gear and pinions. XV. To remove brake mechanism. XVI. To remove trails. I. To Remove Recoil Cylinder. 1. Remove valve turning gear cover (take out four ⅜” bolts attaching it to the piston rod bracket). 2. Remove valve turning gear, valve turning arm and connecting-rod as a unit by removing split pin, nut, and connecting rod pin from trunnion cap, right. 3. Remove piston rod (remove lash wire and two 3/16” split pins) slide piston rod gear forward and remove. 4. Remove ¼” locking screw from top of piston rod bracket. 5. Remove 3/16” cylinder retainer screw and loosen cylinder retainer, but do not remove retainer. 6. Remove brass spring-rod plugs from rear ends of both spring rods. 7. Screw spring compressor eye into rear of left spring rod. Make loop in compressor and attach double sheave close to cradle. Attach single sheave to lunette by means of loose cord of sheave rope. 8. Man pulling rope with from four to six men, retract gun not less than 10”, and secure rope to lunette. 9. Remove cylinder retainer, slide cylinder forward until free of groove in gun and remove cylinder. Handle carefully. 10. Allow gun to return to battery slowly by slacking off on pull rope. II. To Disassemble Recoil Cylinder. Note.—The interior parts of recoil cylinder are made with great accuracy to insure proper operation and must be handled with care to avoid injury. 1. Remove recoil cylinder from carriage. (See I.) 2. Drain recoil cylinder by resting on blocks at front and rear, removing both filling plugs and drain plug, and tipping rear end up to allow all oil to flow out of drain-plug hole. 3. Unscrew buffer-rod nut from rear cylinder head, draw out buffer rod until wrench can be applied on flats, and remove nut. Push rod back into cylinder. 4. Remove lower split pin from gland lock, swing gland lock back until free of notches in gland, and loosen gland with gland wrench. Unscrew front cylinder head with special wrench. Threads may be started by striking handle of wrench with soft hammer. Do not hold cylinder in a vise. 5. Draw out piston rod slowly, supporting it at both ends as it leaves cylinder. Hold recoil valve in cylinder with ends of fingers. Keep receptacle under front of cylinder to catch surplus oil.