Tennant ATLV 4300 Service Manual page 167

Power Steering
2 Series
Steering Control Units
Dust Seal
Quad Seal
11 Lubricate and install the dust seal (see Figure 4 for
correct seal orientation).
12 Install the centering springs in the spool. It is best to
install the two flat pieces first. Next, install the curved
pieces, three at a time.
13 Fit the retaining ring over the centering springs.
14 Apply a light coating of clean hydraulic fluid to the
spool and slide it into the sleeve. Be sure the centering
springs fit into the notches in the sleeve.
15 Install the pin (see Figure 3).
16 Apply a light coating of petroleum jelly to the inner
edge of the dust and quad seals.
17 Put the thrust bearing and races into the housing. The
thrust bearing goes between the two races (see Figure 2).
18 Apply a light coating of clean hydraulic fluid to the
spool and sleeve assembly and slide it into the housing.
Important: Do not damage the dust or quad seals.
19 Clamp the housing in a vise as shown in Figure 5. Use
just enough clamping force to hold the housing securely.
Figure 5
Thrust Bearing
and Race (2)
Figure 4
20 Lubricate and install a new o-ring seal in the groove in
the housing.
21 Install the wear plate and align the holes in the wear
plate with threaded holes in the housing.
Note: The holes in the wear plate are symmetrical.
22 Install the drive, be sure the slot in the drive engages
the pin.
23 Lubricate and install a new o-ring seal in the groove in
the wear plate.
24 Install the gerotor and align the screw holes.
25 Lubricate and install a new o-ring seal in the groove in
the gerotor ring.
26 Lubricate and install a new o-ring and seal ring in the
groove in the gerotor star.
27 Install the spacer.
28 Install end cap and seven cap screws. Tighten cap screws,
in a crisscross pattern, to 16 -18 Nm [140 -160 lb-in].
29 Remove the SCU from the vise.
30 Install the relief valve/check or check ball and plug. Use
a new o-ring and tighten the plug to 17 Nm [150 lb-in].
5