Service and Repair Manual

AN 01-25CN-2

PARAGRAPH 6

  h. Extend the piston rod beyond the piston enough to insert the piston rod in a wooden block clamp with the cap pin in a vertical position. Punch the pin from the cap with a hammer and punch, and by using a tool such as the handle of a spanner wrench, turn the cap from the piston rod. Remove the piston rod from the vise and wooden block clamp.

  i. Pull the piston rod and pawl from the piston, exercising extreme care not to injure the pack. ing cups on the pawl and piston rod as they are pulled from the piston past the square broached holes. Use a light screwdriver with a curved end to depress the packing cup edges as they are pulled past the broached holes. If this precaution is not taken, the edges of the cups will be torn or cut and will not be fit for further service.

  j. Place the cylinder in a vise with aluminum-covered jaws and turn the bearing out of the cylinder with a spanner wrench.

  k. The snap ring and spring may be removed from the cylinder cap, if it is desired, by depressing the end of the snap ring with a pair of pliers and removing the ring. Tip the cap down and the spring will fall out.

  1. If there is evidence of leaks around the two pins in the cylinder cap, the pins and cups may be removed for inspection or replacement. To remove the pins and cups, cut the tock wires on both nuts on the cap and remove the nuts. The pins can now be pulled out and the cups removed through the nut openings. The retracting strut is now completely disassembled as illustrated in Fig. 105.

3. TO ASSEMBLE THE RETRACTING STRUT.

  a. Before assembling the retracting strut, wash all parts with alcohol and be sure the parts are free of chips and other foreign matter. Blow out all parts with compressed air if available.

  b. Place the cylinder in a vise with aluminum-covered jaws. Wet the packing cups on the bearing with hydraulic oil (Spec. 3586) and screw the bearing into the cylinder end. If there was a shim on the original installation, be sure to replace the shim on the bearing. Tighten the bearing in place with a spanner wrench. Do not tighten excessively.

  c. Wet the packing cups on the piston rod and slide the piston rod the piston. Be careful not to foul the cups on the sharp edges of the square broached holes. Use 2 screwdriver with a curved end or a similar tool and depress the edges of the cups as they slide past the broached holes.

  d. Wet the packing cups on the pawl and slide the pawl onto the piston rod and into the piston. Be sure that the collar on the pawl is outboard. Carefully guide the pawl cups through the square broached holes.

  e. If the cylinder cap pins and cups have been removed, wet the cups with hydraulic oil and insert them into the nut holes. Exercise extreme care in this operation that the edges of the cups are not cut or scored by the threads in the nut holes. When the cups are properly- seated, replace the pins in the nuts and screw the nuts into their respective openings. Lock wire the nuts. The cylinder is ready for installation on the piston rod.

  f. Push the piston rod part way into the cylinder and insert the end in a wooden block clamp. Secure the clamp in a vise. Take the cylinder Cap in one hand and drop the spring into the cap with the collar up. Line up one of the slots on the spring with the pin hole in the cap and install the snap ring. Screw the cap onto the piston rod and line up the pin holes on both assemblies. Insert the pin and tap it into place with a light hammer. Stake both ends of the pin.

  g. Release the piston rod from the wooden block clamp and wet the packing cups on the cap and piston with hydraulic oil (Spec. 3586). Insert the piston assembly into the cylinder and turn the cylinder and piston up in a vertical position resting on the cap. This position will keep the pawl in the proper location while the locks are inserted into the square broached holes in the piston. Insert the upper row of locking segments first and allow the cylinder to move down over this row of locks to retain them in place while the bottom locks are inserted in the broached holes. Carefully guide the cylinder over the lower rows of locks. Start the cap into the cylinder and turn it up by hand as far as possible. If there was a shim on the cap in the original installation, be sure that it is replaced. Be sure that the piston protrudes through the bearing at the opposite end of the cylinder.