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SECTION 6A

POWER STEERING SYSTEM

DESCRIPTION AND OPERATION

GENERAL DESCRIPTION

The power steering system consists of three components: the power steering pump, the power steering fluid reservoir and the power steering rack and pinion gear. The power steering pump is a vane-type pump providing hydraulic pressure for the system and is powered by the engine. It draws on the power steering fluid reservoir, which in turn is connected to the power steering gear. A pressure-relief valve inside the flow control valve limits the pump pressure. The power steering rack and pinion gear has a rotary control valve, which directs hydraulic fluid coming from the power steering pump to one side or the other side of the rack piston. The integral rack piston is attached to the rack. The rack piston converts hydraulic pressure to a linear force, which moves the rack to the left or the right. The force is then transmitted through the inner and the outer tie rods to the steering knuckles, which turn the wheels.

COMPONENT LOCATOR

POWER STEERING


UAA6010
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  1. Power Steering Oil Reservoir
  2. Power Steering Oil Reservoir Cap
  3. Power Steering Oil Reservoir Sponge
  4. Power Steering Oil Reservoir Shield
  5. Power Steering Oil Reservoir Nut
  6. Return Line
  7. Pump Pressure Pipe
  8. Clamp
  9. Supply Line Hose
  10. Clamp
  11. Power Steering Pump Bolt
  12. Power Steering Pump Bracket Bolt
  13. Power Steering Pump
  14. Power Steering Gear

DIAGNOSTIC INFORMATION AND PROCEDURES

POWER STEERING SYSTEM PRESSURE TEST

Tools Required

KM-354-B Power Steering Pump Testing Unit
Check the fluid pressure as follows to determine whether the trouble is in the pump or the gear unit.

Test Procedure

  1. Check the power steering fluid level and the serpentine accessory drive belt tension. Refer to "Checking and Adding Fluid" in this section and Section 6B, Power Steering Pump.
  2. Disconnect the high pressure line at the pump. Use a small container to catch any fluid.
  3. Connect the hose of the pressure test gauge kit KM-354-B to the power steering pressure hose from the power steering pump.
  4. Place the gear selector lever in PARK (automatic transaxle-equipped vehicle) or NEUTRAL (manual transaxle-equipped vehicle). Set the parking brake.
  5. Open the gauge valve fully.
  6. Start the engine and let it idle.
  7. Turn the steering wheel from lock-to-lock several times to warm the fluid to operating temperature.
  8. Increase the engine speed to 1,500 rpm.

Notice : The power steering pump could be damaged if the valve is fully closed for more than 5 seconds.

  1. Close the gauge valve fully, and read the pressure. The pump pressure with the valve closed should be between 8,041kPa to 8,728kPa (1,166psi to 1,266psi).
  2. Immediately open the gauge valve fully.
  3. Turn the steering wheel all the way to the left and the right. If the pressure is within the specified limits, the problem is not in the pump. Check the power steering gear for leaks.
  4. Remove the pressure gauge and connect the pressure hose.
  5. Do bleeding procedure.

POWER STEERING SYSTEM LEAK TEST

General Procedure

Inspect the following :

Important : Verify the exact point of the leak. The point from which the fluid is dripping is not necessarily the point at which the system is leaking. When service is required, clean the leak area upon disassembly, replace the leaking seal, check the component sealing surfaces for damage and reset the torque bolt to specifications. Where required.

External Leak Check

The purpose of this procedure is to pinpoint the location of the leak. In some cases, the leak can be easily located, but seepage-type leaks may be harder to find. To locate seepage leaks, use the following method:
  1. With the engine off, wipe dry the complete power steering system.
  2. Check the power steering fluid level in the pump's reservoir. Adjust the fluid level as necessary. Refer to "Checking and Adding Fluid" in this section.

Notice : Do not hold the steering wheel at a stop for any length of time as this can damage the power steering pump.

  1. Start the engine. Turn the steering wheel counterclockwise and clockwise from stop to stop several times.
  2. Find the exact area of the leak and repair it.

MAINTENANCE

BLEEDING THE POWER STEERING SYSTEM

If the power steering hydraulic system has been serviced, an accurate fluid level reading cannot be obtained until the air is bled from the system. Follow these steps to bleed the air from the system.
  1. Turn the wheels all the way to the to the left and add the power steering fluid to the MIN mark on the fluid level indicator.

Notice : When adding fluid or marking a complete fluid change, always use DEXRON®-III power steering fluid. Failure to use the proper fluid will cause hose and seal damage and fluid leaks.

  1. Start the engine. With the engine running at fast idle, recheck the fluid level. If necessary, add fluid to bring the level up to the MIN mark.
  2. Bleed the system by turning the wheels from side to side without reaching the stop at either end. Keep the fluid level at the MIN mark. The air must be eliminated from the fluid before normal steering action can be obtained.
  3. Return the wheels to the center position. Continue running the engine for 2 to 3 minutes.
  4. Road test the car to be sure the steering functions normally and is free from noise.
  5. Recheck the fluid level as described in steps 1 and 2. Make sure the fluid level is at the MAX mark after the system has stabilized at its normal operating temperature. Add fluid as needed.

CHECKING AND ADDING FLUID

Notice : When adding fluid or making a complete fluid change, always use DEXRON®-III power steering fluid. Failure to use the proper fluid will cause hose and seal damage and fluid leaks.

  1. The power steering fluid level is indicated either by marks on a see-through fluid reservoir or by marks on a fluid level indicator on the fluid reservoir cap.
  2. If the fluid is warmed up to 66°C (150°F), the fluid level should be between the MAX and MIN marks. Add fluid as needed.
  3. If the fluid is cool, 21°C (70°F), the fluid level should be at the MIN mark. Add fluid as needed.

REPAIR INSTRUCTIONS

ON-VEHICLE SERVICE


UAA6A020
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POWER STEERING FLUID RESERVOIR

Removal and Installation Procedure

  1. Siphon the power steering fluid from the fluid reservoir.
  2. Loosen the hose clamps and remove both hoses from the fluid reservoir.
  3. Remove the power steering fluid reservoir mounting nuts.
  4. Remove the power steering fluid reservoir.
    5. Installation Notice
    Tightening Torque
    10 N•m (7 lb-ft)

UAA6A030
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POWER STEERING PUMP HOSES AND PIPES

(Left-Hand Drive Shown, Right-Hand Drive Similar)

Removal and Installation Procedure

  1. Siphon the power steering fluid from the fluid reservoir.
  2. Disconnect the pressure line pipe from the outlet connection on the power steering pump and return hose from the inlet connection on the power steering fluid reservoir.
    3. Installation Notice
    Tightening Torque
    28 N•m (21 lb-ft)

    UAA6A040
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  3. Remove the pressure line pipe bracket bolt from the alternator.
    4. Installation Notice
    Tightening Torque
    8 N•m (6 lb-ft)

    UAA6A050
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  4. Raise and suitably support the vehicle.
  5. Remove the return line bracket bolt from the cross-member.
    6. Installation Notice
    Tightening Torque
    8 N•m (6 lb-ft)

    UAA6A060
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  6. Disconnect the pressure line fitting nut from the power steering gear inlet.
  7. Disconnect the return line fitting nut from the power steering gear outlet.
  8. Lower the vehicle.
  9. Remove the pressure line and the return line from the vehicle.
    10. Installation Notice
    Tightening Torque
    Power Steering Gear Inlet-to-Pressure Line Fitting Nut
    28 N•m (21 lb-ft)
    Tightening Torque
    Power Steering Gear Outlet-to-Return Line Fitting Nut
    28 N•m (21 lb-ft)

UAA6A070
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POWER STEERING FLUID SUPPLY HOSE

Removal and Installation Procedure

  1. Siphon the power steering fluid from the fluid reservoir.
  2. Remove the power steering fluid supply hose bracket bolts from the radiator.
    3. Installation Notice
    Tightening Torque
    8 N•m (6 lb-ft)

    UAA6A080
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  3. Disconnect the pressure line hose from the inlet connection on the power steering pump and supply hose from the outlet connection on the power steering fluid reservoir.
  4. Remove the power steering fluid supply hose from the vehicle.

SPECIFICATIONS

GENERAL SPECIFICATIONS

Application
Description
Capacity
1.0 Liter (1.1 qt)
Lubricant
Power Steering Fluid DEXRON®-III

FASTENER TIGHTENING SPECIFICATIONS

Application
N•m
Lb-Ft
Lb-In
Power Steering Fluid Reservoir Mounting Nut
10
7
89
Power Steering Pump-to-Pressure Line Pipe Fitting Nut
28
21
-
Alternator-to-Pressure Line Pipe Bracket Bolt
8
6
71
Crossmember-to-Return Line Bracket Bolt
8
6
71
Power Steering Gear Inlet-to-Pressure Line Fitting Nut
28
21
-
Power Steering Gear Outlet-to-Return Line Fitting Nut
28
21
-
Radiator-to-Supply Hose Bracket Bolt
8
6
71

SPECIAL TOOLS AND EQUIPMENT

SPECIAL TOOLS TABLE


UAA6A090
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KM-354-B Power Steering Pump Testing Unit


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