AN 01-25CN-2

PARAGRAPH 4

(8) TO DISASSEMBLE THE RETRACTING STRUT. (See Fig. 67.)    (a) Place the cylinder in a wooden block clamp and insert the clamp in a vise.    (b) Remove the cotter pins, nuts, washers, and bolts attaching the lug to the piston. Slide the lug off the piston and piston guide.    (c) Remove the cylinder bushing with a spanner wrench.    (d) Move to the opposite end of the cylinder and remove the cap assembly and shims.    (e) Grasp the piston guide and push the piston out of the cylinder far enough to free the two locks from the square broached holes. Remove the locks and pull the piston and guide completely out of the cylinder.    (f) Tip the piston with the guide end up until the actuator, follower, and spring drop out of the piston end.    (g) Remove the cup from the forward end of the cylinder and remove the cylinder. The cylinder and piston are now completely disassembled as illustrated in figure 67. (9) TO ASSEMBLE THE RETRACTING STRUT.    (a) Clean all parts thoroughly with alcohol and blow out with compressed air if available.    (b) Replace all worn packing cups and other parts where necessary.    (c) Insert the spring and follower into the end of the piston.    (d) Coat the cups on the actuator with hydraulic oil, Spec. 3586, (never use mineral oil) and slide the actuator into the piston. Be very careful not to tear or injure the edges of the packing cups as they enter the cylinder and are pushed past the square broached holes in the lock assembly.    (e) Wet the cup that fits into the forward end of the cylinder with hydraulic fluid and replace

the cup in the cylinder. Be extremely careful not to damage the cup surface on the threads in the end of the cylinder.    (f) Replace the two locks in the square broached holes and insert the piston and guide into the cylinder, guide end first.    (g) Screw the bushing into the cylinder until it is tight. Do not tighten the bushing excessively.    (h) Wet the packing cup on the cap with hydraulic fluid, replace the shim, and screw the cap into the aft end of the cylinder.    (i) Check the piston for backlash. The motion of the piston must be adjusted to .002 or .005 inch. Adjustment can be made by adding or removing a shim between the cap and cylinder.    (j) Slide the lug over the piston guide and onto the piston, line up the piston hole with those in the lug, and insert the rear bolt.    (k) Before installing the retracting strut in the airplane, test the strut for leaks. Use only hydraulic fluid (Spec. 3586) for this leak test. The test must be made with the piston in the mid-stroke position. The strut must not leak at 2500 p.s.i.. If there is no evidence of leakage at the end cap, end bushing, or the two hydraulic line pipe fittings the strut is ready to reinstall in the fuselage.    (1) After the cylinder has been checked for proper piston motion and leakage, it is ready to be reinstalled in the fuselage. To install the retracting cylinder in the fuselage, reverse the procedure outlined in (7), (a) through (h). (10) ADJUSTMENT OF THE TAIL WHEEL DOORS-After the tail wheel shock absorber strut is installed in the airplane, the adjustable links to the tail wheel doors must be adjusted. With the tail wheel in the retracted position', install the turnbuckle on one side only. Attach to the door, adjust the turnbuckle, and then disconnect the upper end. Repeat for the opposite side. Lower the tail wheel and attach the turnbuckles. Be sure that the turnbuckle barrels are lock wired.

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