78-31-01
ALL ú ú N01 Page 508 ú Jun 10/97
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
S 825-044-N00
(16) Find the correct shim thickness and install shims with the steps that follow:
(a) Measure the thickness of the clay at the three points, with
equal distances between them, at the bottom of the engine
vee-groove.
1) The clay thickness must be 0.00-0.10 inch.
2) The average of the three values must be a minimum of 0.04
inch.
(b) Examine the transfer dye or petroleum jelly on the fire seal.
1) The width of the transfer dye or petroleum jelly must be
0.25 inch or more along the full length of the fire seal.
(c) Clean the petroleum jelly from the strut and fire seals.
NOTE: Cut the edges of the shims to make them the same shape____
as the fittings. Install the shims with the countersink
in the thicker shim lamination.
(d) Measure the clay thickness at each of the three upper
bifurcation compression pads (shim 1, 3, 5, 16 locations).
(e) Make the 0.125-inch shims equal to the difference between the
clay thickness and the specified clearance of 0.06 inch.
NOTE: The specified clearances are limits which apply after____
the shims are installed. These clearances let the
thrust reverser vee-blade and compression pads seal
during the engine operation.
(f) Apply the primer to the shims.
1) Let the primer become dry.
(g) Install the shims with the countersunk in the thicker shim
lamination.
(h) Install the shim (1) with the screws (2).
(i) Install the shims (3, 5, 16) with the screws (4 and 6).
(j) Measure the clay thickness at each of the four lower
bifurcation compression pads (shim 7, 17, 29 locations).
(k) Make the 0.125 inch shims equal to the difference between the
clay thickness and the specified clearance of 0.06 inch.
(l) Apply the primer to the shims.
1) Let the primer become dry.
(m) Install the shims with the countersink in the thicker shim
lamination.
(n) Install the shim (7) with the screws (8 and 9), washers (10),
and nuts (11).
(o) Install the shim (29) with the screws (30).
(p) Install the shim (17) with the screws (18).
(q) Measure the clay thickness for the seven bumper pad shims at
the latch fittings (shim 12, 19, 24 locations).
(r) Make the 0.125 inch shims equal to the sum of the temporary
shim and the clay thickness.
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78-31-01
ALL ú ú N01 Page 509 ú Jun 10/97
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
(s) Make the shims the necessary thickness with a tolerance of plus or minus 0.003 inch.
NOTE: It can be necessary to change the dimension of the
____
countersink holes.
(t)
Before the installation, apply the primer to the shim.
(u)
Let the primer become air dry for 10 minutes until the primer feels tacky.
NOTE: You can make the adhesive thinner by 50 % with MEK.
____
(v)
Install the bumper pad shims (24) and spacers (25) with the
screw (26), washer (27), and nut (28).
(w)
Install the bumper pad shims (19) and spacers (20) with the
screw (21), washer (22), and nut (23).
(x)
Install the shim (12) for the torque box latch with the bolts (13), washers (14), and nuts (15).
S 415-039-N00
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