Ford Mustang/Cougar 1964-1973 Repair Guide

Power Steering System




See Figures 1 and 2

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Fig. Fig. 1: Common power steering linkage components

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Fig. Fig. 2: Power steering system components

Proper lubrication of the steering linkage and the front suspension is very important for the operation of the power steering systems. Check the steering gear box for sufficient lubricant by removing the filler plug and checking the level. Add enough fluid gear oil S.A.E. 90 to bring the oil level to the filler plug hole if necessary.

Do not use a pressure gun to add fluid gear oil since the pressure will force the oil out of the steering gear box.Air Bleeding

Air bubbles in the power steering system must be removed from the fluid. Be sure the reservoir is filled to the proper level and the fluid is warmed up to the operating temperature. Turn the steering wheel through its full travel three or four times until all the air bubbles are removed. [cf2]Do not hold the steering wheel against its stops. Recheck the fluid level.

Fluid Level Check

  1. Run the engine until the fluid is at the normal operating temperature. Then, turn the steering wheel through its full travel three or four times and turn OFF the engine.
  3. Check the fluid level in the steering reservoir. On cars built before 1968, the fluid level is checked by removing the reservoir cap and looking in the filler tube for the fluid level. On 1968 and later cars, a dipstick is provided in the filler tube that shows the proper fluid level. If the fluid level is low, add enough fluid to raise the level to the Full mark on the dipstick or filler tube. Use automatic transmission fluid, type A.

Pump Belt Check

  1. Inspect the pump belt for cracks, glazing, or worn places. Using a belt tension gauge, check the belt adjustment. The amount of tension varies with the make of car and the condition of the belt. New belts (those belts used less than 15 minutes) require a higher figure. The belt deflection method of adjustment may be used only if a belt tension gauge is not available. The belt should be adjusted for a deflection of 3 / 8 - 1 / 2 inches.

Fluid Leaks

Check all possible leakage points (hoses, power steering pump, or steering gear) for loss of fluid. Start the engine and rotate the steering wheel from lock-to-lock several times. Tighten all loose fittings and replace any defective lines or valve seats.

Turning Effort

Check the effort required to turn the steering wheel after aligning the front wheels and inflating the tires to the proper pressure.

  1. With the vehicle on dry pavement and the front wheels straight ahead, set the parking brake and turn the engine ON.
  3. After a short warm-up period, turn the steering wheel back and forth several times to warm the steering fluid.
  5. Attach a spring scale to the steering wheel rim and measure the pull required to turn the steering wheel one complete revolution in each direction. The effort needed to turn the steering wheel should not exceed the limits given in the specifications.

This test may be done with a torque wrench on the steering wheel nut. See the section on manual steering for a discussion of this test.

Power Steering Hose Inspection

Inspect both the input and output hoses of the power steering pump for worn spots, cracks, or signs of leakage. Replace the hose if it is defective, being sure to reconnect the replacement hose properly. Many power steering hoses are identified as to where they are to be connected by special means, such as fittings that will only fit on the correct pump fitting, or hoses of special lengths.

Checking the Oil Flow and Pressure Relief Valve in the Pump Assembly

When the wheels are turned hard right or hard left, against the stops, the oil flow and pressure relief valves come into action. If these valves are working, there should be a slight buzzing noise. Do not hold the wheels in the extreme position for over three or four seconds because, if the pressure relief valve is not working, the pressure could get high enough to damage the system.


When test-driving to check the power steering, drive at a speed between 15 and 20 mph. Make several turns in each direction. When a turn is completed, the front wheels should return to the straight-ahead position with very little help from the driver.

If the front wheels fail to return as they should and yet the steering linkage is free and properly adjusted, the trouble is probably due to misalignment of the power cylinder or improper adjustment of the spool valve.

  1. Lubricate the sector shaft journal and install the sector shaft and cover. With the cover moved to one side, fill the gear with steering gear lubricant (0.90 lb.). Push the cover and the sector shaft into place and install the two top housing bolts. Do not tighten the bolts until checking to see that there is some lash between the ball nut and the sector gear teeth. Hold or push the cover away from the ball nut and tighten the bolts to 30-40 ft. lbs.
  3. Loosely install the sector shaft adjusting screw locknut and adjust the sector shaft mesh load as given earlier. Tighten the adjusting screw locknut.