Hydraulic Pressure in P/S Circuit Check

WARNING: This page is about a different car, the 2006 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.

After cleaning joint of high pressure hose and P/S pump thoroughly, disconnect hose from pump and install special tool (oil pressure gauge, attachment and hose).
CAUTION: Take care not to cause damage to A/C condenser during service operation, if equipped.

Special Tool

(A): 09915-77410

(B): 09915-77420

Fig 1: Identifying Hydraulic Pressure In P/S Circuit Components
Courtesy of SUZUKI OF AMERICA CORP.
Check each connection for fluid leakage and bleed air. Refer to P/S SYSTEM AIR BLEEDING PROCEDURE .
With engine idling, turn steering wheel and warm up engine till temperature of fluid in tank rises to 50 - 60 °C (122 - 140 °F).

Fig 2: Identifying Power Steering Fluid Temperature
Courtesy of SUZUKI OF AMERICA CORP.
Check back pressure by measuring hydraulic pressure with engine idling and hands off steering wheel. When back pressure is higher than specified values, check control valve and piping for clogging.
Back pressure

Lower than 1000 kPa (10 kg/cm ² , 142 psi)

Fig 3: Identifying Back Pressure
Courtesy of SUZUKI OF AMERICA CORP.
Check relief pressure.
1. Increase engine speed to about 1500 r/min. (rpm). Close gauge valve gradually while watching pressure increase indicated by gauge and take reading of relief pressure (maximum hydraulic pressure).
  If it is higher than specified values, possible cause is malfunction of relief valve.
  
  If it is lower than specified values, possible cause is either failure of P/S pump or settling of relief valve spring.
  
  Relief pressure when gauge value is closed
  
  7650 - 8350 kPa (76.5 - 83.5 kg/cm ² , 1088 - 1187 psi)
  
  CAUTION: Be sure not be close gauge valve for longer than 10 seconds.
  
  Fig 4: Identifying Relief Pressure (Gauge Value Closed)
  Courtesy of SUZUKI OF AMERICA CORP.
2. Open gauge valve fully and increase engine speed to about 1500 r/min. (rpm). Then turn steering wheel to the left or right fully and take reading of relief pressure.
  If it is higher than specified values, possible cause is malfunction of relief valve.
  
  If it is lower than specified values, possible cause is failure in steering gear box. Replace gear box.
  
  Relief pressure when gauge value is opened
  
  7650 - 8350 kPa (76.5 - 83.5 kg/cm ² , 1088 - 1187 psi)
  
  CAUTION: Be sure not to hold steering wheel at fully turned position for longer than 10 seconds.
  
  Fig 5: Checking Relief Pressure (Gauge Value Opened)
  Courtesy of SUZUKI OF AMERICA CORP.