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Pressure Test

  1. Start engine and let idle for approximately 2 minutes. Record flow. If flow is less than 1.6 gallons per minutes (6.1 L per minutes) on Explorer and Ranger or 2 gallons per minute (7.6L per minute) on Bronco, "E" and "F" Series, pump may require repair. Continue test.
  2. If pressure is greater than 150 psi (11 kg/cm2 ), check hoses for restrictions. Partially close valve to build up pressure to 740 psi (52 kg/cm2 ) for C-II pumps or 620 psi (44 kg/cm2 ) on Saginaw pumps.
  3. If flow drops below specification, disassemble pump and replace cam pack. If pressure plates are cracked or worn, they must be replaced.
  4. Completely close and partially open gate valve 3 times. Do not close valve for more than 5 seconds. Record highest reading each time. If pressure is higher or lower than specified, repair or replace flow control valve. Refer to appropriate PRESSURE TEST SPECIFICATIONS TABLE.
    PRESSURE TEST SPECIFICATIONS

    Application Idle Pressure psi (kg/cm2 ) Relief Pressure psi (kg/cm2 )
    Ford C-II Pump
    Model HBC-KC 740 (52) 1050-1230 (74-86)
    Model HBC-KE 740 (52) 1400-1530 (98-108)
    PRESSURE TEST SPECIFICATIONS

    Application Idle Pressure psi (kg/cm2 ) Relief Pressure psi (kg/cm2 )
    Saginaw Pump
    Model HBA-HA/ HB 620 (44) 1250-1450 (88-102)
    Ford C-II Pump
    Model HBC-JX 740 (52) 1300-1530 (91-108)
    Model HBC-JY 740 (52) 1350-1530 (95-108)
  5. Set engine speed at 1500 RPM. Record flow. If flow varies more than 1 gallon (3.8L) per minute from pressure measured in step 1), flow control valve in pump must be repaired or replaced.
  6. Turn steering wheel to left and right stops. Pressure should be nearly the same as maximum relief pressure. Flow should drop below .5 gallon (1.9L) per minute.
  7. If pressure and flow are not as specified, steering gear is leaking internally. Remove steering gear. Remove flow control valve. Repair or replace damaged parts. Check rack piston and valve seals for damage.
  8. If pressure and flow are good, turn steering wheel slightly in both directions and release quickly while watching pressure gauge. Needle should move from normal backpressure reading and snap back as wheel is released.
  9. If gauge reacts slowly, or sticks, rotary valve in steering gear is sticking. Repair or replace rotary valve.
  10. If system is severely contaminated, both hoses, control valve, and pump must be disassembled and cleaned. If problem still exists, check ball joints, linkage and other front suspension members.
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