Hydraulic Pressure

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

To measure hydraulic pressure correctly, be sure to complete all the items in "INSPECTION", prior to performing the measurement. < Refer to INSPECTION , General Diagnostic Table. >
Do not leave the valve of pressure gauge closed or hold the steering wheel at lock for 5 seconds or more in any case, this can damage the oil pump.
Before attaching a pressure gauge, place cloth at locations where fluid is expected to spill. Wipe off any spilt fluid completely after the measurement.

Regular pressure measurement
1. Connect the ST1, ST2 and ST3.
  ST1 925711000 PRESSURE GAUGE
  
  ST2 34099AC020 ADAPTER HOSE B
  
  ST3 34099AC010 ADAPTER HOSE A
2. Remove the air intake duct.
  - Non-turbo model: < Refer to REMOVAL , Air Intake Duct. >
  - Turbo model: < Refer to REMOVAL , Air Intake Duct. >
3. Disconnect the pressure hose from the pump.
4. Using the gasket (Part No. 34621AC021) and bolt (Part No. 34620AC010), install the ST2 to pump instead of pressure hose.
  - Non-turbo model
    
    Fig 1: Identifying Suction Hose And Pressure Hose (Non-Turbo Model)
    Courtesy of SUBARU OF AMERICA, INC.
  - Turbo model
    
    Fig 2: Identifying Suction Hose And Pressure Hose (Turbo Model)
    Courtesy of SUBARU OF AMERICA, INC.
5. Attach the ST3 to the end of pressure hose which is removed from pump.
6. Replenish power steering fluid up to the specified level.
7. Open the valve, and start the engine.
8. Measure the regular pressure.
  ST1 925711000 PRESSURE GAUGE
  
  ST2 34099AC020 ADAPTER HOSE B
  
  ST3 34099AC010 ADAPTER HOSE A
  
  Fig 3: Measuring Regular Pressure Of Valve Using Tools
  Courtesy of SUBARU OF AMERICA, INC.
  
  Service limit:
  
  981 kPa (10 kgf/cm ² , 142 psi) or less
9. If it is not within the specification, replace the faulty part for the following problems. (Pipe or hose clogged, leaks from fluid line, and mixture of foreign matter in fluid line)
Measure the relief pressure.
1. Using the ST, measure the relief pressure.
2. Close the valve.
3. Measure the relief pressure.
  ST1 925711000 PRESSURE GAUGE
  
  ST2 34099AC020 ADAPTER HOSE B
  
  ST3 34099AC010 ADAPTER HOSE A
  
  Fig 4: Measuring Relief Pressure Of Valve Using Tools
  Courtesy of SUBARU OF AMERICA, INC.
  
  Service limit:
  
  Non-turbo model:
  
  7, 350 - 8, 050 kPa (75 - 82 kgf/cm ² , 1, 066 - 1, 167 psi)
  
  Turbo model:
  
  8, 100 - 8, 800 kPa (83 - 90 kgf/cm ² , 1, 174 - 1, 276 psi)
4. If the torque is not within specified range, replace the oil pump.
Measure the working pressure.
1. Using the ST, measure the working pressure.
2. Open the valve.
3. Measure the working pressure of control valve by turning steering wheel from stop to stop.
  ST1 925711000 PRESSURE GAUGE
  
  ST2 34099AC020 ADAPTER HOSE B
  
  ST3 34099AC010 ADAPTER HOSE A
  
  Fig 5: Measuring Working Pressure Of Control Valve
  Courtesy of SUBARU OF AMERICA, INC.
  
  Service limit:
  
  Non-turbo model:
  
  7, 350 - 8, 050 kPa (75 - 82 kgf/cm ² , 1, 066 - 1, 167 psi)
  
  Turbo model:
  
  8, 100 - 8, 800 kPa (83 - 90 kgf/cm ² , 1, 174 - 1, 276 psi)
4. If it is out of specification, measure the steering effort. < Refer to MEASUREMENT OF STEERING EFFORT , INSPECTION, General Diagnostic Table. > If it is not within specification, replace the control valve itself or control valve and pinion as a single unit, using new parts.
  If it is not within specification, replace the control valve itself or control valve and pinion as a single unit, using new parts.