Power Steering Control Unit

DISASSEMBLY

Fig. 10 Removing Power Steering Control Unit:

Fig. 11 Power Steering Control Unit Exploded View:

Fig. 12 Sensor Orifice Removal:

Install components as they are removed, and keep all components in order to ensure proper assembly.

1. If control unit is being removed with steering gear in vehicle, drain power steering fluid, remove steering gear shield, clean dirt from control unit and fluid lines, then disconnect fluid lines and plug lines and open fittings.
2. Remove control unit retaining bolts, control unit, port orifices and O-rings, Fig. 10.
3. Remove 2 flange bolts, valve body cap and gasket, Fig. 11.
4. Remove cut-off valve and spring, then separate valve body from port housing.
5. Remove seal and dowel pins from valve port housing.
6. Remove rollers from control valve by pushing control valve out one side of housing then the other. When removing rollers, hold plungers with fingers to prevent them from popping out.
7. Remove plungers, return springs and control valve, Fig. 11.
8. Remove sensor orifice and O-ring using 1/16 inch drill bit, Fig. 12.
9. Push dampening orifice and O-ring from valve body using 1/16 inch drill bit.

INSPECTION
1. Clean all components with suitable solvent.
2. Inspect valve body bores for scoring scratches and wear, and replace as needed.
3. Inspect cut-off and control valves for scoring, scratches and wear.
4. Insert valves into valve body bores and ensure valves slide freely, without binding or side play. Valve body, control valve and cut-off valve are a matched set and must be replaced as an assembly.
5. Inspect plungers for scoring, scratches and wear, and ensure plungers slide freely in bores without binding or side play.
6. Inspect plunger springs and replace if damaged or collapsed.
7. Ensure sensor and dampening orifices are clear and free from damage.

ASSEMBLY

Fig. 13 Control Valve & Plunger Installation:

Replace all O-rings and seals, and coat O-rings and friction surfaces with power steering fluid during assembly.

1. Install new O-rings on sensor and dampening orifices and press orifices into valve body.
2. Insert control valve into valve body, then install plungers and return springs, Fig. 13.
3. Shuttle control valve in valve body, as needed, and install rollers.
4. Install dowel pins and seal on port housing.
5. Install valve body, cap seal and cap, then torque flange bolts to 7 ft. lbs. Ensure mating surfaces of valve body and cap are flush on upper side.
6. Ensure control valve shuttles freely in valve body and returns to neutral position.
7. Position orifices and new O-rings on steering gear, then install control valve and seal, and torque retaining bolts to 7 ft. lbs. Ensure control valve does not interfere with pinion holder pin and that O-rings remain properly aligned during installation.