PROPEL TRANSMISSION
SUBSECTION 9B
The hydraulic amplifier assembly is a preci-
sion built component and must be handled
with care. Avoid any contact of objects with
the feedback wire protruding from the base of
the assembly. Do not let metal particles or ob-
jects come in contact with the magnets.
10. Remove the hydraulic amplifier assembly by carefully
lifting straight up on the base of the assembly.
11. Remove O-rings (08 and 20) from the base of the hy-
draulic amplifier assembly. Do not remove hydraulic
amplifier screens (21) unless they are to be replaced with
new ones.
12. Insert a pin extractor into bushing locating pin (09).
Tighten down the pin extractor thumbscrew to grip the in-
Figure 9B-29. Cleaning the Air Gap
side diameter of the locating pin.
13. Withdraw the bushing locating pin from valve body
3. Clean all remaining parts in a clean commercial solvent.
(27).
Permit parts to air dry or dry using clean dry compressed air.
14. Use a 3/16 inch Allen wrench, to remove six cap-
4. Visually inspect inlet orifice assemblies (12) and re-
screws (28) and lockwashers (29). Remove end plates (14).
place if damaged or foreign matter is present.
15. Remove seal plates (15) and O-rings (16).
5. Inspect the hydraulic amplifier assembly for damaged
coil leads, and a bent or broken feedback wire.
16. Insert the edge of a screwdriver under the lip of inlet
orifice (12) and remove the inlet orifice assemblies and O-
6. Inspect all O-ring sealing surfaces for scratches, scor-
rings (11) from body (27). Unless they are new, the inlet
ing or other damage.
orifice assemblies should be discarded and replaced each
7. Replace all O-rings.
time they are removed.
17. Check that spool (30) moves freely within bushing (31).
ASSEMBLY. Assembly should be performed in as clean an
If the spool does not move freely, completely remove the
environment as possible. Exercise care to avoid cutting or
bushing from the valve body as follows:
nicking O-rings when installing them on parts, and when
installing parts containing O-rings to prevent subsequent
A. With a 1/2 inch diameter nylon dowel and a small ham-
leakage. Assemble the controller as follows (see Figure 9B-
mer, tap bushing (31) out of the body.
30):
B. Gently shake the bushing and spool or alternately push
1. Install hollow hex plug (17) if it has been removed.
on the ends of the spool to loosen the spool and allow the
material binding the spool to fall free.
2. Insert all six O-rings (18) on bushings (31).
C. Remove the spool. Exercise care when handling the
3. Orient the controller on a clean flat surface in such a
bushing and spool to prevent damaging parts.
manner that the mounting face is away from the assem-
bler. Look in the large center hole in top of valve body (27)
18. Remove six O-rings (18) from bushing (31).
and install bushing (31) in the body as shown in Figure 9B-
19. Do not remove hollow hex plug (17) unless it is dam-
30. Center the bushing pin locating hole directly below this
aged or defective.
large center hole.
NOTE
CLEANING AND INSPECTION. Clean and inspect the com-
Normally, the bushing can be installed in the control-
ponents of the controller as follows (see Figure 9B-30):
ler body with reasonable hand force. If necessary, tap
the bushing into the body using a 1/2 inch diameter
nylon dowel and a small hammer.
Most solvents react with O-ring compounds.
4. Lubricate spool (30) with clean filtered hydraulic fluid.
Remove all O-rings from parts before clean-
Install the spool in bushing (31) with the spool slot end
ing.
oriented toward the right side of the valve body. This oper-
ation must be performed with care. Any misalignment will
1. Clean bushing (31) and spool (30) by immersing them in
cause the spool to bind and not slide fully or easily into the
a clean commercial solvent.
bushing.
2. Clean the air gaps of hydraulic amplifier assembly (07) by
5. Insert bushing locating pin (09) into the large center hole
blowing clean, dry air through the air gaps (see Figure 9B-
in top of the valve body, using the pin extractor.
29).
9B-16
