GM Prizm/Nova 1985-1993 Repair Guide

Power Steering Pump

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Both the Nova and Prizm use a 10-vane hydraulic pump to pressurize the system. The pump is driven by a multi-ribbed belt. The pump employs a flow control valve which is sensitive to engine rpm. As the engine speed increases, the valve reduces the pressure flow to the steering gear. When the engine is at low rpm or at idle, the valve delivers higher pressure to the rack, offsetting the higher resistance of a slow moving tire. This variable ratio power steering offers a combination of high power assist at low speeds, thus making parking and turning easier, as well as firmer, less sensitive steering reactions at highway speeds.

REMOVAL & INSTALLATION



Nova with VIN Code 4 engine

See Figures 1 and 2

  1. Place a drain pan below the pump.
  2.  
  3. Remove the air cleaner assembly
  4.  
  5. Remove the clamp from the fluid return hose. Disconnect the pressure and return hoses at the pump. Plug the hoses and suspend them with the ends upward to prevent leakage.
  6.  
  7. Loosen the pump pulley nut. Push down on the belt to keep the pulley from turning.
  8.  
  9. Remove the adjusting bolt.
  10.  
  11. Remove the pivot bolt and remove the drive belt.
  12.  
  13. Remove the pump assembly.
  14.  
  15. Remove the pump bracket.
  16.  
  17. Remove the pulley. Be careful not to lose the small woodruff key between the pulley and the shaft.
  18.  

To install:
  1. Place the pump in position and temporarily install the 2 mounting bolts.
  2.  
  3. Install the pump bracket and tighten the bolts to 29 ft. lbs.
  4.  
  5. Install the pump pulley and the woodruff key. Tighten the pulley nut to 32 ft. lbs.
  6.  
  7. Install the drive belt, making certain that all the grooves of the belt are engaged on the pulley. Adjust the belt to the proper tension.
  8.  
  9. Connect the pressure and return lines to the pump. Tighten the fittings to 33 ft. lbs. Install the clamp on the return hose.
  10.  
  11. Install the air cleaner assembly.
  12.  
  13. Fill the reservoir to the proper level with power steering fluid and bleed the system.
  14.  
  15. After the car has been driven for about an hour, double check the belt adjustment.
  16.  



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Fig. Fig. 1: Nova power steering pump components - 1985-88 VIN code 4 engine



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Fig. Fig. 2: There is only 1 correct way to install the drive belt.

Nova with VIN Code 5 engine

See Figures 3, 4 and 5

  1. Place a drain pan below the pump.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Disconnect the return hose from the pump, then disconnect the pressure hose. Plug the lines immediately to prevent fluid loss and contamination.
  6.  
  7. Remove the splash shield under the engine.
  8.  
  9. Remove the pulley nut. Push down on the drive belt to prevent the pulley from turning.
  10.  
  11. Loosen the idler pulley nut and loosen the adjusting bolt.
  12.  
  13. Remove the drive belt.
  14.  
  15. Loosen the pump pulley and woodruff key. Don't lose the woodruff key.
  16.  
  17. Remove the upper mounting bolt.
  18.  
  19. Loosen the lower mounting bolt and pivot the pump downward.
  20.  
  21. Disconnect the oil pressure switch connector.
  22.  
  23. Remove the pump bracket mounting bolts; remove the pump from the engine with the bracket attached.
  24.  
  25. Remove the pulley from the pump and the pump from the bracket.
  26.  
  27. Remove the idler pulley bracket.
  28.  

To install:
  1. Mount the pump on the bracket and loosely install the lower mounting bolt.
  2.  
  3. Temporarily insert the pulley onto the pump shaft without the woodruff key. The pulley cannot be installed after the pump is installed on the engine.
  4.  
  5. Install the pump and bracket onto the engine. Tighten the upper mounting bolts to 29 ft. lbs.
  6.  
  7. Connect the oil pressure switch connector.
  8.  
  9. Install the idler pulley bracket; tighten the 3 mounting bolts to 29 ft. lbs.
  10.  
  11. Tighten the lower mounting bolts to 29 ft. lbs.
  12.  
  13. Install the woodruff key into the pulley and install the drive belt. Make certain the ribs of the belt are properly placed on all the pulleys.
  14.  
  15. Tighten the pulley nuts on the pump and idler to 28 ft. lbs.
  16.  
  17. Connect the pressure hose and tighten its fitting to 33 ft. lbs.
  18.  
  19. Connect the return hose.
  20.  
  21. Install the air cleaner and install the lower splash shield.
  22.  
  23. Adjust the belt to the proper tension.
  24.  
  25. Fill the reservoir to the proper level with power steering fluid and bleed the system.
  26.  
  27. After the car has been driven for about an hour, double check the belt adjustment.
  28.  



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Fig. Fig. 3: Nova power steering pump components - 1988 VIN code 5 engine



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Fig. Fig. 4: Idler pulley and adjusting bolt - 1988 VIN code 5 engine



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Fig. Fig. 5: Removing the upper pump mounting bolt - 1988 VIN code 5 engine Location of oil pressure switch connector - 1988 VIN code 5 engine

1989-90 Prizm

See Figure 6

  1. Place a drain pan below the pump.
  2.  
  3. Elevate and safely support the vehicle.
  4.  
  5. Remove the right front wheel.
  6.  
  7. Place a floor jack under the engine block and support it. Use a broad piece of wood to spread the load evenly and prevent damage.
  8.  
  9. Remove the bolt from the right side engine mount and lower the engine about 50mm to gain access to the lower power steering pump through-bolt.
  10.  
  11. Working through the right wheel well, remove the lower pump through-bolt.
  12.  
  13. Disconnect the fluid lines from the pump and plug them immediately.
  14.  



Click image to see an enlarged view

Fig. Fig. 6: Removing the pressure hose. The GM tool shown makes the job easier.

  1. Remove the upper mounting bolt from the pump and remove the pump.
  2.  

To install:
  1. Place the pump in position and install the mounting bolts. Tighten them to 29 ft. lbs.
  2.  
  3. Raise the engine to its normal position and install the engine mount bolt, tightening it to 69 ft. lbs.
  4.  
  5. Connect the fluid lines to the pump and tighten the pressure hose fitting to 34 ft. lbs.
  6.  
  7. Install the belt and adjust it to the proper tension.
  8.  
  9. Install the right front wheel.
  10.  
  11. Remove the jack and drain pan from under the engine.
  12.  
  13. Lower the vehicle to the ground.
  14.  
  15. Fill the reservoir to the proper level with power steering fluid and bleed the system.
  16.  
  17. After the car has been driven for about an hour, double check the belt adjustment.
  18.  

1991-92 Prizm
BASE AND LSi MODELS

See Figure 7

  1. Disconnect the negative battery cable. Remove the air cleaner.
  2.  
  3. Remove the power steering pump drive belt.
  4.  
  5. Loosen the power steering hose retaining clip and remove the return hose from the power steering pump.
  6.  
  7. Remove the pressure hose from the pump using a injection line wrench J-29698 or equivalent.
  8.  
  9. Remove the upper mounting bolt from the pump.
  10.  
  11. Remove the vacuum hoses from the power steering switch. Remove the 3 bolts retaining the pump bracket mount and the 2 from the engine block and the one from the engine mount.
  12.  
  13. Remove the lower mounting bolt and the power steering pump from the vehicle.
  14.  
  15. Installation is the reverse order of the removal procedure. Torque the power steering pump mounting brackets to 29 ft. lbs. (39 Nm). Connect the pressure hose to the power steering pump union bolt and torque it to 32 ft. lbs. (44 Nm). Adjust the belt tension and bleed the system.
  16.  



Click image to see an enlarged view

Fig. Fig. 7: Power steering pump mounting - 1991-92 Base and LSi models and all 1993 models

GSi MODELS

See Figure 8

  1. Disconnect the negative battery cable. Place a drain pan under the vehicle.
  2.  
  3. Remove the windshield washer reservoir retaining bolt; position the reservoir out of the way.
  4.  
  5. Loosen the drive pulley retaining nut. Use a J-35416 or equivalent adjusting screw wrench to keep the pulley from turning while loosening the retaining nut.
  6.  
  7. Raise and support the vehicle safely. Loosen the jam nut on the idler pulley. Lower the vehicle and remove the power steering pump drive belt.
  8.  
  9. Remove the drive pulley retaining nut from the shaft and remove the pulley from the pump.
  10.  
  11. Remove the power steering pressure lines from the pump.
  12.  
  13. Remove the 2 power steering pump retaining bolts and remove the pump from the bracket.
  14.  
  15. Installation is the reverse order of the removal procedure. Torque the power steering pump mounting brackets to 29 ft. lbs. (39 Nm). Connect the pressure hose to the power steering pump union bolt and torque it to 32 ft. lbs. (44 Nm). Adjust the belt tension and bleed the system.
  16.  



Click image to see an enlarged view

Fig. Fig. 8: Power steering pump mounting - 1991-92 GSi models

1993 VEHICLES
  1. Disconnect the negative battery cable. Remove the air cleaner.
  2.  
  3. Remove the power steering pump drive belt.
  4.  
  5. Loosen the power steering hose retaining clip and remove the return hose from the power steering pump.
  6.  
  7. Remove the pressure hose from the pump using a injection line wrench J-29698 or equivalent.
  8.  
  9. Remove the upper mounting bolt from the pump.
  10.  
  11. Remove the vacuum hoses from the power steering switch. Remove the 3 bolts retaining the pump bracket mount and the 2 from the engine block and the one from the engine mount.
  12.  
  13. Remove the lower mounting bolt and the power steering pump from the vehicle.
  14.  
  15. Installation is the reverse order of the removal procedure. Torque the power steering pump mounting brackets to 29 ft. lbs. (39 Nm). Connect the pressure hose to the power steering pump union bolt and torque it to 32 ft. lbs. (44 Nm). Adjust the belt tension and bleed the system.
  16.  

BLEEDING THE POWER STEERING SYSTEM



Any time the power steering system has been opened or disassembled, the system must be bled to remove any air which may be trapped in the lines. Air will prevent the system from providing the correct pressures to the rack. The correct fluid level reading will not be obtained if the system is not bled.

  1. With the engine running, turn the wheel all the way to the left and shut off the engine.
  2.  
  3. Add power steering fluid to the COLD mark on the indicator.
  4.  
  5. Start the engine and run at fast idle for about 15 seconds. Stop the engine and recheck the fluid level. Add to the COLD mark as needed.
  6.  
  7. Start the engine and bleed the system by turning the wheels from left to right 3 or 4 times.
  8.  
  9. Stop the engine and check the fluid level and condition. Fluid with air in it is a light tan color. This air must be eliminated from the system before normal operation can be obtained. Repeat Steps 3 and 4 until the correct fluid color and fluid level is obtained.
  10.  

 
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