7-4. Cleaning, Inspection, and Repair
that at this position, adjusting screw is free to turn with no
play or looseness in the cap hub (9). If holes in adjusting
Clean all parts thoroughly to remove buildup of spray
nut and adjusting screw line up, insert a new roll pin (5).
residue and dirt. Inspect and repair the synchromatic
If holes do not align, drill new hole 0.062 in. diameter in a
windmill assembly as described in paragraph 4-23, step
location that will miss existing hole.
e, with the following additional steps:
(b) If a new adjusting nut only is
a. Check condition of threads on adjusting screw
required, turn the nut down on the adjusting screw, and
(8), adjusting nut (6), and actuator (4).
then back off slightly, as noted in step (a), preceding.
b. Check base and cap hubs (3 and 9) carefully
Check to see that adjusting screw is free to turn with no
for cracks, distortion, and for condition of blade hub
play or looseness. If hole in nut does not line up with
bearing surfaces. Smooth out any rough areas which
hole in adjusting screw, drill a new hole through the
might affect blade adjustment.
adjusting screw. Use the hole in the adjusting nut as a
Note:
guide, and drill hole of same size as in nut (0.062 inch
Base and cup hubs are shipped as a
diameter). Secure nut with new roll pin (5).
matched set. If either needs to be
(c) If a new adjusting screw is required,
replaced, replace both with a matched
find position of adjusting nut on adjusting screw as
set.
described in step (b), preceding. After determining
c. Place blades (2) in boiling water for 30 min-
correct position, drill hole through adjusting screw in line
utes to restore flexibility.
with hole in nut. Secure nut with new roll pin (5)).
b. Complete assembly of synchromatic windmill
7-5. Assembly
assembly as instructed in paragraph 4-23, step. f.
CAUTION
Assemble the synchromatic windmill assembly using
Do not try to turn blade angle when
a. Assemble cap hub assembly (1) as follows:
resistance to adjustment is noted.
(1) Lightly lubricate threads of adjusting screw
Internal damage to mechanism will
(8) with instrument grease per Military Specification MI-
result if parts are binding.
G-23827.
c. Check blade adjustment mechanism
for
(2) Place washer (7) over short end of
operation. Turn adjusting nut (6) to adjust blade angle to
adjusting screw.
maximum positions. Blade must be adjustable from
(3) Place short end of adjusting screw
position "I" to position "F" as noted on figure 4-8 without
through cap hub (9) and install second washer (7) over
evidence of sticking or binding. If adjustment cannot be
adjusting screw.
made freely, do not try to force the blade adjustment.
CAUTION
Remove the cap hub assembly (1, fig. 7-1) and turn the
Position of adjusting nut on adjusting
actuator in the desired direction. Replace cap assembly
and again test adjustment. Repeat this procedure until
screw is critical. Adjusting screw
full adjustment of the blade angle can be made.
must be free to turn in cap hub, but
must not have excessive play or
7-6. Installation
looseness.
(4) Attach adjusting nut (6) to adjusting screw
Attach the synchromatic windmill fan assembly to the
(8), using one of the following steps, as applicable:
pump brake drum as described in paragraph 4-23, step
(a) If reusing both the adjusting nut and
g.
adjusting screw, turn adjusting screw down until it is just
tight. Then back off by the amount noted during
Section II. BRAKE ASSEMBLY
the brake shoes are returned to their normal position by
7-7. General
the brake springs (5, fig. 7-2). This action allows the
synchromatic windmill assembly and pump to operate.
The brake assembly (fig. 7-2) is attached directly to the
spray fluid pump assembly (8). The brake assembly
consists of a pair of brake shoes (4) contained inside a
7-8. Removal
brake drum (2). Actuation of the brake arm by the brake
lever (16, fig. 410) causes the brake shoes to expand
a. Remove the synchromatic windmill assembly
against the brake drum.
This action stops the
from brake drum by removing three attachment bolts (20,
synchromatic windmill assembly from turning, thereby
fig. 42).
stopping the pump. When the brake lever is released,
7-3
