landrover Workshop Repair Guides

Land Rover Workshop Service and Repair Manuals

Steering Lock ECU Operation > < Hydraulic Circuit Operation|Page 276
Page 227
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STEERING

57-24

DESCRIPTION AND OPERATION

Steering in Right Turn Position

Circuit shows steering rotary valve in right turn position, at high vehicle speed and with rapid steering corrections. The 

Servotronic transducer valve is fully open and the maximum hydraulic reaction is limited by the cut-off valve.

Return fluid control groove
Radial groove
Feed fluid control groove
Radial groove
Axial groove
Feed fluid control edge
Feed fluid radial groove
Return fluid control edge
Return fluid chamber

10 Cut-off valve
11 Radial groove
12 Servotronic transducer
13 Feed fluid radial groove
14 Radial groove
15 Orifice
16 Balls
17 Compression spring

18 PAS fluid reservoir
19 Torsion bar
20 Valve rotor
21 Reaction piston
22 Reaction chamber
23 Centering piece
24 Pressure relief/flow limiting valve
25 PAS pump
26 Inner track rod
27 Pinion
28 Valve sleeve
29 Steering rack
30 Rack housing
31 Power assist cylinder – right
32 Piston
33 Power assist cylinder – left

When the steering wheel is turned to the right, the steering rack and piston moves to the left in the piston bore. The 
valve rotor is rotated to the right (clockwise) and pressurised fluid is directed over the further opened feed fluid control 
edges and to the associated axial grooves, the radial groove and via an external pipe to the left power assist cylinder 
chamber. The pressure applied to the piston from the left power assist cylinder chamber provides the hydraulic 
assistance.

An adaptable pressure build-up is achieved by the partially or fully closed feed fluid control edges restricting or 
preventing a connection between the fluid pressure inlet and the other axial grooves connected to the radial groove.

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Steering Lock ECU Operation > < Hydraulic Circuit Operation|Page 276