34
Repair Information
– Series 2 Variable Displacement Pump
Install the servo piston cover
on the servo piston adjustment
screw. Install about half way
down the adjustment screw.
Next, install a new threaded
seal and special washer. Install
the threaded seal first and then
the special washer. The bev-
eled side of the special washer
must face the sealing washer.
(see Figure 65)
Install the lock nut on the servo
piston adjustment screw. Do
not tighten this lock nut at this
time. Final servo piston adjust-
ment will take place later on
during reassembly. (see Figure
66)
Lubricate and install the servo
piston assembly into the pump
housing. Install into the op-
posite side of the pump hous-
ing the speed sensor port is
located . The flat side of the
servo piston must also be per-
pendicular to, and facing, the
center of the pump housing.
Install the four servo cover retaining cap screws. Torque cap screws
to 16 ft. lbs. [21,7 Nm] to 17 ft. lbs. [23 Nm]. (see Figure 67)
Using a square, make sure the
flat side of the servo piston is
perpendicular to the pump
housing face. (see Figure 68)
Install the remaining servo pis-
ton cover and remaining four
servo cover retaining cap
screws. Torque cap screws to
16 ft. lbs. [21,7 Nm] to 17 ft.
lbs. [23 Nm]. (see Figure 69)
Complete Reassembly
Before reassembly, clean all parts and assemblies. Inspect and
replace damaged parts and assemblies. When reworking parts,
do not use course grit paper, files or grinders on finished sur-
faces. Replace all gaskets and seals.
Lubricate all seals with petroleum jelly (Vaseline) for retention
during reassembly. Freely lubricate all bearings and finished sur-
faces with clean hydraulic fluid.
The front bearing cup is a
slip fit in the pump hous-
ing. When replacement is
necessary, simply slip it in
the pump housing. (see
Figure 61)
Shown here are the seals
used to seal the servo pis-
ton to the pump hosing.
Two each, O-rings and
back up rings. (see Figure
62)
Lubricate and install the
two new seals and back-
up rings into the servo pis-
ton bore located in the
pump housing. Install the
black sealing ring first and
then the blue back-up ring.
Caution must be used not
to twist or kink these seals
during installation. (see
Figure 63)
Lubricate and install new
seals on both the servo
piston covers. (see Figure
64)
Figure 61
Figure 63
Figure 64
Figure 65
Figure 66
Figure 67
Figure 69
Figure 68
Figure 62