MANUAL UPDATE: P/S PRESSURE CHECK PROCEDURE

VEHICLES AFFECTED: 1988-89 W-CAR, 1990 CHEVROLET LUMINA W/2.5,2.8,3.1

This power steering pressure test procedure replaces the procedure found in the following Service Manuals.

Division Model Year Pages --------- ----------- ------ Buick 1988 3-7

Buick 1989 3-11

Oldsmobile 1988 3-7

Oldsmobile 1989 3-11

Pontiac 1988 3-7

Pontiac 1989 3-11

Chevrolet 1990 3-11 and 3-14

POWER STEERING SYSTEM TEST PROCEDURE:

2.8/3.1L Engine - Figure 1

Tools Required:

J 5176-D Power Steering Pressure Tester J 5176-30 Hose Assembly J 25323-A Power Steering System Analyzer J 38049-2 Tube Assembly J 38049-3 Tube Nut

1. Remove fuse block shield. 2. Remove A.I.R. pump belt (manual transaxle only). 3. Remove serpentine belt from power steering pump pulley. 4. Remove retaining clip from high pressure pipe. 5. Remove high pressure pipe from pump. - Place a drain pan under vehicle to catch any fluid that may drain. 6. Position high pressure pipe towards right strut. 7. Install serpentine belt. 8. Install J 5176-D as shown in Figure 1. 9. Open the valve on J 5176-D. 10. Start engine and allow system to reach operating temperature. Stop engine and check fluid level, adding fluid if required. When system is at normal operating temperature, the pressure reading on the gauge (valve open) should be under 1034 kPa (150 psi). If this pressure is above 1034 kPa (150 psi) stop engine, check the hoses for restriction. 11. Start the engine and let it idle. Close valve fully 3 times (to shut-off flow completely), and record the highest pressure attained each time. DO NOT leave valve fully CLOSED for more than 5 seconds.

a. If the pressures recorded are high and within 345 kPa (50 psi) of each other, the pump is functioning within specifications.

* b. If the pressures recorded are not within 345 kPa (50 psi) of each other, the control valve in the pump is sticking. Remove, but do not disassemble the control valve assembly, clean and remove any burrs using crocus cloth or fine hone. If the system contains foreign material, flush it.

Notice: Do not attempt to disassemble the flow control valve.

c. If the pressures recorded are within 345 kPa (5o psi) of each other, but low pressure, replace the control valve assembly and recheck. If the pressures are still low, inspect the rotor and vanes.

12. Shut off engine and remove J 5176-D. 13. Partially remove serpentine belt. 14. Install high pressure pipe to pump and close retaining clip to high pressure pipe. 15. Install serpentine belt to power steering pump pulley. 16. Install A.I.R. pump belt (manual transaxle only). 17. Install fuse block shield. 18. Bleed system and check fluid level.

2.5L ENGINE ----------- Figure 2

Tools Required:

J 5176-D Power Steering Pressure Tester J 5176-30 Hose Assembly J 25323-A Power Steering System Analyzer J 38049-1 Hose Assembly J 38049-25 Tube Assembly J 38049-3 Tube Nut

1. Raise vehicle, refer to GENERAL INFORMATION (SECTION OA). 2. Remove pressure pipe from pump. - Place a drain pan under vehicle to catch any fluid that may drain. 3. Install J 38049-25 to pump and to J 5176-30. 4. Lower vehicle, partially. 5. Install J 51276-D as shown in Figure 2. 6. Open the valve on J 5176-D or J 25323. 7. Start engine and allow system to reach operating temperature. 8. Start the engine and let it idle, Close valve fully 3 times (to shut-off flow completely), and record the highest pressure attained each time. DO NOT leave valve fully CLOSED for more than 5 seconds.

a. If the pressures recorded are not, within 345 kPa (50 psi) of each other, the pump is functioning within specifications.

b. If the pressures recorded are not, within 345 kPa (50 psi) of each other, the control valve in the pump is sticking. Remove but do not disassemble the control valve assembly, clean it and remove any burrs using crocus cloth or fine hone. If the system contains foreign material, flush it.

c. If the pressures recorded are within 345 kPa (50 psi) of each other, but low pressure, replace the flow control valve assembly and recheck. If the pressures are still low, inspect the rotor and vanes.

9. Shut-off engine and remove J 5176-D. 10. Raise vehicle, refer to GENERAL INFORMATION (SECTION OA). 11. Install high pressure pipe to pump. 12. Lower vehicle. 13. Bleed system and check fluid level.

ILLUSTRATIONS:

LC0010-3-W-RA Figure 1 Power Steering Pressure Gauge Connections (2.8/3.1L Engine)

LC0012-3-W-RA Figure 2 Power Steering Pressure Gauge Connections (2.5L Engine)

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.