Tennant ATLV 4300 Service Manual page 165

Power Steering
2 Series
Steering Control Units
Disassembly
Cleanliness is extremely important when repairing hydraulic
Steering Control Units (SCU). Work in a clean area. Before
disconnecting the hydraulic lines, clean the port area of the
SCU. Before disassembly, drain the oil, then plug the ports and
thoroughly clean the exterior of the SCU. During repairs,
always protect machined surfaces.
1 Remove the seven cap screws and disassemble the SCU as
shown in Figure 1.
2 Remove the plug and manual steering check as shown in
Figure 1.
Note: The manual steering check may be a check ball or a
check/relief valve.
3 Slide the spool and sleeve from the housing (see Figure 2).
Housing
Dust
Seal
Wear
Plate
O-ring
Seal
O-ring
Manual Steering
Check/Relief Valve
Quad
Seal
Gerotor
Drive
Spacer
O-ring
Seal
Plug
Figure 1
4 Remove the thrust bearing and bearing races.
5 Remove the quad seal.
6 Using a small blade screwdriver, carefully pry the dust seal
from the housing.
Important: Do not damage the dust seal seat.
Spool and Sleeve
Thrust
Bearing
Bearing Race (2)
Figure 2
Cap
Screw
End
(7)
Cap
Seal
Ring
O-ring
O-ring
3