Disassembly of Hoist Cylinder

TM 10-3930-609-35

3-70. Disassembly of Hoist Cylinder (fig. 3-13)

d. Inspect external surfaces of secondary cylinder

and secondary plunger for scratches, pitting, scoring,

a. Remove bleed screw and washer.

upset metal and other surface damage.

b. Withdraw secondary cylinder approximately 12

e. Inspect check valve for free return flow.

inches from primary cylinder; then, unscrew and remove

packing retainer from secondary cylinder, being careful

not to scratch or otherwise damage surface of

3-73.

Repair and Replacement of Hoist Cylinder

secondary cylinder.

Parts

c. Remove wiper ring and two packings from

a. Replace all cracked or distorted parts.

packing retainer.

b. Repair minor thread damage with a tap, thread

d. Carefully withdraw and remove secondary

file or thread chaser.

plunger from secondary cylinder.

c. Remove minor surface defects on surfaces of

e. Remove spacer from bore in secondary cylinder

secondary cylinder and secondary plunger with crocus

or from secondary plunger.

cloth or with minor honing.

f. Unscrew plug from end of secondary plunger

d. Replace all packings and wiper rings with new

and take out check valve.

parts at each assembly.

g. Remove retaining ring from groove in secondary

3-74. Reassembly of Hoist Cylinder (fig. 3-13)

plunger; then, remove sleeve from end of secondary

plunger.

Note

h. Remove packing from groove in sleeve and

Apply grease GAA to rubber

remove packing from groove in secondary plunger.

packings and wiper rings before

i. Remove retaining ring from internal groove in

assembly.

primary cylinder and withdraw packing retainer from

primary cylinder.

a. With secondary cylinder inserted into primary

j. Remove wiper ring from packing retainer.

cylinder as far as possible, install packing in recess

k. Continue to slide secondary cylinder out of

between primary cylinder and secondary cylinder.

primary cylinder.

Remove packing-from secondary

b. Place wiper ring in packing retainer.; then,

cylinder. If packing does not emerge from primary

carefully pass packing retainer over end of secondary

cylinder as secondary cylinder is being withdrawn, slide

cylinder and press into primary cylinder. Install retaining

secondary cylinder back into primary cylinder; then,

ring in internal groove of primary cylinder to retain

using a pick, carefully pry out packing, being careful not

packing retainer.

to scratch or otherwise damage surface of secondary

cylinder.

c. Place packing in groove at lower end of

secondary plunger and install packing in external groove

of sleeve.

Note

Secondary cylinder cannot be

d. Install sleeve on lower end of secondary plunger

completely removed from primary

and secure with retaining ring.

cylinder.

e. Insert check valve into lower end of secondary

plunger and secure with plug.

3-71.

Cleaning Disassembled Parts of Hoist

f. Carefully slide secondary plunger all the way

Clyinder

into secondary cylinder.

a. Clean all .removed metallic parts with SD and

g. With partially assembled cylinder in vertical

dry with soft lint-free cloth.

position, pour one pint of rust preventive oil (MIL-C-

b. Slide secondary cylinder out of primary cylinder

16173) into space between secondary cylinder and

as far as possible and carefully clean exposed surface

secondary plunger.

of secondary cylinder with cloth moistened with SD.

h. Install packing in internal groove of packing

retainer, install packing on shoulder of packing retainer

3-72. Inspection of Hoist Cylinder Parts

and install wiper ring in recess of packing retainer.

a. Inspect all threaded parts and parts with tapped

i. Carefully place packing retainer over end of

holes for stripped threads or other thread damage.

secondary plunger. and engage threads on packing

b. Inspect packing retainers for scratches, burrs

retainer with internal threads in secondary cylinder.

and upset metal.

j. Withdraw secondary cylinder from primary

c. Inspect cylinders and plunger for cracks and

cylinder approximately 12 inches; then, while holding

distortion.

secondary cylinder, tighten packing retainer

3-23