Component Tests and General Diagnostics

Fig. 4 Power Steering Pressure Gauge Connections:

SYSTEM PRESSURE TEST
NOTE: When performing system test procedures, power steering pressures can easily exceed 1000 psi. Extreme caution must be exercised when performing these tests to prevent personal injury.

1. Disconnect pressure hose from pump.
2. Connect a spare pressure hose to pump, then connect pressure gauge tool No. J-5176-D, or equivalent, between both hoses, Fig. 4.
3. Open valve on gauge, then start engine and allow it to reach operating temperature. Check fluid level and add if necessary.
4. Pressure reading should be 80-125 psi. Refer to chart for proper pressure readings; if pressure is more than specified, check hoses for restrictions and poppet valve on steering gear for proper assembly.
5. Close valve fully three times for not more than five seconds each time. Refer to chart for pressure readings (models without T/C style pump).
6. If pressures recorded are high enough and within 50 psi of each other, the pump is operating normally.
7. If pressures recorded are high enough but are not within 50 psi of each other, the control valve in the pump is sticking. Remove but do not disassemble control valve and clean it with crocus cloth or a fine hone to remove any burrs. Flush system if fluid appears to be dirty.
8. If pressures recorded are less than specified replace control valve and recheck. If pressures are still low, inspect pump rotor and vanes.
9. If pump pressure meets specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with maximum pump pressure recorded. If pressure is not the same (at both stops) as maximum pressure, steering gear is leaking internally and must be disassembled and repaired.
10. Turn off engine and remove pressure gauge and spare hose, then reconnect pressure hose and restore fluid level to full level.