1987 Ford Aerostar Van Cargo, 2.3 A, AutomaticFACTORY OEM SERVICE PROCEDURE

Pressure Test

NOTE: For testing Ford vehicles, use Power Steering Analyzer D79-33610-A with flow meter.
  1. Start engine and record the flow. If flow is below 1.6 gals./min. (6.1 L/min.) on Bronco II and Ranger or 2 gals./min. (7.6 L/min.) on all others, pump may require repair. At this point, however, continue test.
  2. If pressure is above 150 psi (10.5 kg/cm2 ), check hoses for restrictions. Partially close valve to build up pressure to 740 psi (51.8 kg/cm2 ) for Ford pumps and 620 psi (43.6 kg/cm2 ) for Saginaw pumps.
  3. If flow drops below specifications, disassemble pump and replace cam pack. If pressure plates are cracked or worn, replace them.
  4. Completely close and partially open the gate valve 3 times. Do not close valve more than 5 seconds. Record the highest reading each time. If pressure is higher or lower than specified, repair or replace flow control valve. See PRESSURE TEST SPECIFICATIONS  chart.
  5. Set engine speed at 1500 RPM. Record the flow. If flow varies more than 1 gal./min. (3.8 L/min.), flow control valve in pump should be repaired or replaced.
  6. Turn steering wheel to the left and right stops. Pressure should be nearly the same as the maximum relief pressure. Flow should drop below .5 gals./min. (1.9 L/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 is good, turn steering wheel slightly in both directions and release quickly while watching the pressure gauge. The needle should move from the normal backpressure reading and snap back as the wheel is released.
  9. If the gauge reacts slowly, or sticks, the rotary valve in the steering gear is sticking. Repair or replace rotary valve. If system is severely contaminated, both hoses, control valve, and pump must be disassembled and cleaned.
NOTE: If problem still exists, check ball joints, linkage, and other front suspension members.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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