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Pressure Test

NOTE: For testing, use Power Steering Analyzer (D79L-33610-A) with flow meter.
  1. Start engine and let idle for approximately 2 minutes. Record flow. If flow is less than 1.6 gals. per min. (6.1L per min.) on Aerostar, Bronco II and Ranger or 2 gals. per min. (7.6L per min.) 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. See POWER STEERING PUMP article. 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 PRESSURE TEST SPECIFICATIONS  table.
  5. Set engine speed at 1500 RPM. Record flow. If flow varies more than 1 gal. (3.8L) per min. 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 gal. (1.9L) per min.
  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.
PRESSURE TEST SPECIFICATIONS

Application (1) Idle Pressure (1)(2) Relief Pressure
Ford C-II Pump
Model HBC-KC 740 (52) 1050-1230 (74-86)
Ford C-II Pump
Model HBC-KE 740 (52) 1400-1530 (98-108)
(1) Readings in psi (kg/cm2 ).
(2) Measure with steering wheel turned to extreme right or left position.
PRESSURE TEST SPECIFICATIONS

Application (1) Idle Pressure (1)(2) Relief Pressure
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)
Ford C-II Pump
Model HBC-JY 740 (52) 1350-1530 (95-108)
(1) Readings in psi (kg/cm2 ).
(2) Measure with steering wheel turned to extreme right or left position.
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