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Power Steering General Servicing: Testing

NOTE: Before testing power steering system, check fluid level, belt tension, pump pulley, tire pressure and engine idle speed.
  1. Remove high pressure line from pump and attach Adapter Fitting (J-5176-11) to pump. Using Pressure Gauge (J-5176-02) and Adapter (J-5176-12), connect gauge to hose.
  2. Open valve fully. Run engine until fluid reaches normal operating temperature. Check fluid level and add as necessary. With engine at operating temperature, pressure reading should be 80-125 psi (5.6-8.8 kg/cm2 ). If pressure is more than 200 psi (14 kg/cm2 ), inspect system for restrictions or faulty flow control valve.
    CAUTION: To prevent pump damage, DO NOT  hold valve closed for more than 5 seconds in step 3).
  3. Alternately close and open gauge valve fully 3 times while recording highest pressure obtained. Each reading should be at least 1000 psi (70.3 kg/cm2 ) or 1250 psi (87.9 kg/cm2 ) on TC series pumps. TC series pumps can be identified by a square shaped reservoir on side of pump.
  4. If recorded pressures are all within 50 psi (3.5 kg/cm2 ), pump is okay. If pressures are high and not within 50 psi (3.5 kg/cm2 ) of each other, flow control valve is sticking.
  5. If pressure readings are less than 1000 psi (70.3 kg/cm2 ) or 1250 psi (87.9 kg/cm2 ) on TC series pumps, replace flow control valve and retest pump pressure.
  6. If pump meets specification, leave valve open. Turn steering wheel from stop to stop. Record and compare highest pressure with maximum pump pressure.
  7. If pressure at both stops is not similar to maximum pressure, steering gear is leaking internally.
POWER STEERING PUMP PRESSURE TEST SPECS

Application Pressure: psi (kg/cm2 )
4.5L
Idle 80-125 (5.6-8.8)
Relief 1350-1450 (94.9-101.9)
5.0L & 5.7L
Idle 80-125 (5.6-8.8)
Relief 1000-1250 (70.3-84.7)
5.0L Commercial
Idle 80-100 (5.6-7.0)
Relief 1000-1250 (70.3-84.7)
All Other Engines (TC Series Pump)
Idle 80-125 (5.6-8.8)
Relief 1000-1250 (70.3-84.7)
POWER STEERING PUMP FLOW TEST SPECIFICATIONS

Application Flow: Gals./Min. (L/Min.)
4.5L
Minimum 1.32 (5.0)
Maximum 3.10 (11.8)
All Other Engines (TC Series Pump) (1)
(1) Information not available from manufacturer.