Repair Standards - TM-9-2520-249-34-P0071

TM 9-2520-249-34&P

(2) While holding the expander in the

valves should move freely in their bores by their weight

groove, start the seal into the groove at a point

alone. Do not force valves.

diametrically opposite the expander ends.

(2) Inspect the edges of all valve lands.

lubrication is necessary for installation.

All edges should be square and sharp. Do not destroy

(3) Install the seal by hand. Tools or

these sharp edges in cleaning or repair operations.

instruments might damage the seal. Do not stretch the

These sharp edges help prevent the accumulation of

seal any more than is necessary for installation.

substances which might cause the valve to stick in its

(4) Center the piston in the piston bore

bore.

when installing it, to prevent seal damage.

(3) Remove burs with a soft honing stone.

extremely careful to avoid scratching, nicking, or

If necessary, reclean valves to remove gum and dirt.

distorting a Teflon seal. Refer to chapter 7, section IX.

Discard all valves which have other defects.

o. Sheet Metal Parts.

WARNING

(1) Inspect sheet metal parts for bends,

Do not dispose of Teflon seal rings by burning.

cracks, distortion, interference with adjacent parts, and

Toxic gases are produced when Teflon is

loose-welded joints.

burned.

(2) Straighten bent parts. Weld cracks or

5-4.

Repair Standards

loose welds.

a. Clearance and Wear Limits. Data covering

(3) Discard governor oil collector rings if

the size and fits of new parts and wear limit information

any damage is evident.

are given in the repair standards tables in Chapter 7.

p. Installation of Teflon Seals and Expanders.

b. Torque Specifications.

Special torque

(1) Install the expander into the sealring

specifications are given in the text where applicable.

groove so that its ends bend toward the bottom of the

c. Spring Specifications.

Refer to repair

grooves.

standards tables in chapter 7, for spring specifications.

NOTE

Some expanders may require additional

bending to cause them to point toward the

bottom of the groove.

5-3