b. Inspect all moving parts to make sure they have
not been scored or damaged by dirt particles. Smooth
burnished surfaces are normal in many areas. Any
slightly scored parts may be cleaned by hand rubbing
with 600-grit abrasive paper.
c. Prepare all surfaces of control assembly for
assembly as follows:
(1) Place a piece of 600-grit abrasive paper
face up on a piece of plate glass or similar material.
(2) Clean the ends of the star gear first to
remove any sharp grit from the paper which could
(3) Clean both sides of the ring gear, both
sides of the plate, the 14-hole end of the housing, and
the flat side of the end cap.
(4) Stroke each surface across the abrasive
several times and check the results. Any small bright
Figure 8-4. Checking control spool.
areas indicates a burr which must be removed. When
polishing the parts, hold them as flat as possible against
(5) Control assembly.
the abrasive. After 6 to 10
(a) Remove bushing (26) and packing (27)
from control assembly.
Use extreme care when removing
control spool and sleeve. The parts
are closely fitted and must be rotated
slightly as they are withdrawn.
(b) Place port face of housing (38) on a solid
surface and remove the control spool and sleeve from
Do not pry against edge of hole in
housing bore when removing valve
(c) Using a small bent tool or wire, remove
valve seal plug (28) from housing by reaching it through
"out" port and pushing upwards.
See figure 8-5.
Remove packing (29, fig. 8-3).
(d) With housing (38) in vise, control end up,
unscrew check seat (30), using a hex wrench.
(e) Remove housing from vise and tip up.
Figure 8-5. Removing check valve seat plug.
Tap housing lightly with palm of hand and allow check
valve seat (30), ball (31) and spring (32) to fall out into
strokes across the abrasive, check the part to see if it is
polished. After each part is polished, rinse clean in
(f) Remove disks (33) and centering pin (34)
solvent, blow dry with air, and place it where it can
from the control spool and sleeve.
remain absolutely clean until assembly.
(g) Push inside lower edge of spool (35) so
d. Replace all packing and oil seals. Replace all
spool moves toward splined end and remove spool
other parts as authorized.
carefully from sleeve (36).
(h) Push centering spring set (37) out of spring
slot in spool (35).
8-9. Steering Gear Valve, Cleaning, Inspection and
a. Control Assembly, Reassembly
(1) Install clean wooden block in a vise to
a. Clean all parts with cleaning solvent (Fed. Spec.
P-D-680). Cleaning may be done during disassembly
and parts set to dry on clean paper towel.