Tag the spools to assure that each will be
crocus cloth. If burrs and scores are deep, replace valve
reassembled in the body from which it was removed. Do
not interchange the spools in the bodies.
To remove the check valve assemblies, grip
4-5) and spring (4) for distortion, cracks, breaks, or other
damage; if parts are damaged, remove the C-washers
the stem of the check valve with a pliers and pull out the
from the spool and replace with four new C-washers.
plug to release the spring and ball.
Coat parts lightly with engine oil. Check the
relief valve and check valve balls for freedom of
movement in their bores. If the relief valve or ball is not
free to move, replace the relief valve or ball.
Dry cleaning solvent P-D-680 is toxic and
flammable. Wear protective goggles and gloves
and use only in a well ventilated area. Avoid
contact with skin, eyes, and clothes and don't
breathe vapors. Do not use near open flame or
control valve. Note the following:
excessive heat. The flash point is 100°F -
Lubricate all parts with clean engine oil prior to
138°F. (38°C -59°C). If you become dizzy while
Make sure that spools are installed into the
using cleaning solvent, get fresh air immediately
bores of the bodies from which they were removed.
and get medical aid. If contact with eyes is
Install one C-washer (10 and 6) on the spool
made, wash your eyes with water and get
and position the spring (4) on the spool. Compress the
medical aid immediately.
spring and install the second C-washer to retain the
Cleaning and Inspection
When joining the valve bodies together, tighten
Discard all seals and preformed packings;
the nuts on the bolts evenly and alternately to 15 ft/lbs
replace with new parts.
Clean all metal parts in cleaning solvent P-D-
680 and dry thoroughly with compressed air.
Inspect the two spools of the control valve for
Position the hydraulic control valve on the
distortion, cracks, wear, or scoring. Coat the spool lightly
truck; secure with three capscrews, nuts, and
with clean oil and check the fit of the spool in the body.
The parts must provide a close-tolerance fit. If any side
Install the control linkage on the control valve.
play of the spool is perceptible, or if the spool is
Connect the hydraulic lines to the hydraulic
damaged, or sticks in the body, replace the entire valve
control valve (TM 10-3930-632-12).
Inspect all parts of the hydraulic control valve
for burrs; remove burrs by lapping with crocus cloth.
Inspect the valve bores for burrs and scoring;
if scores and burrs are not deep, remove them with
Section V. TILT LOCK VALVE
Paragraphs 4-21, 4-22, 4-24, 4-25 and 4-26 deleted.
Remove the tilt block valve (TM 10-3930-632-12).
Figure 4-6. Tilt Lock Valve, Exploded View.
Change 1 4-10