Home ReviewsRefund
Home/Chevrolet/Lumina/Chevrolet Lumina I (1989-2001)/Repair manual/Electronic Steering/Steering System - Variable Effort
Contents Wiring diagrams Section: Electronic Steering All sections

Steering System - Variable Effort Chevrolet Lumina I

Electronic Steering 2 illustrations ~1182 words

RACK & PINION ASSEMBLY

Pump pressurizes fluid and sends it through the pump's flow control valve to the pinion and valve on the rack and pinion assembly. (Scheme 2) Pinion and valve direct fluid to either side of the piston and rack, depending on turning direction of steering wheel. Piston and rack converts hydraulic pressure into linear force, reducing turning effort.

TROUBLE SHOOTING - NON-ELECTRONIC

Note. See the TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

TESTING - NON-ELECTRONIC

Note. Incorrect fluid level, belt tension and idle speed, as well as a damaged pump pulley, can affect test results. If any of these conditions exists, correct them before testing power steering system.

PRESSURE TEST

  1. On vehicles without Two Flow Electronic (TFE) steering, go to step 3). On TFE-equipped vehicles, check normal system operation. Start engine and turn wheels from side to side. Wheels should turn with minimal effort. Wait 3 minutes and repeat previous step. Increased effort should be required to turn wheels.
  2. If system operation is not as specified, troubleshoot and repair as necessary. If system operation is as specified, connect fused jumper between terminal B8 of multi-function chime module and terminal 4 of DLC, to enable full fluid flow. Go to next step.
  3. Disconnect high pressure line from power steering pump. Connect Power Steering Pressure Tester Kit (J-5176-D), or Power Steering Analyzer (J-25323) with Adapter (J-28579), between high pressure line and power steering pump using spare high pressure hose. Completely open tester valve.
  4. Run engine until fluid reaches operating temperature. Stop engine. Check fluid level. Add fluid if necessary. Start engine. With valve open and engine idling, pressure should be less than 150 psi (10.5 kg/cm 2 ). If pressure exceeds specification, stop engine and check for restrictions in hoses. CAUTION: To prevent pump damage, DO NOT hold gauge valve closed for more than 5 seconds.
  5. Fully close valve for less than 5 seconds and then open it. Repeat process 2 more times, and record highest pressure displayed each time valve is closed. If readings are as specified and within 50 psi (3.5 kg/cm 2 ) of each other, go to step 8). Refer to the «PRESSURE SPECIFICATIONS»(/chevrolet/lumina/i-1989-2001/remont/electronic-steering/#steering-system-variable-effort) table below. If readings are as specified but not within 50 psi (3.5 kg/cm 2 ) of each other, go to next step. If readings are not as specified but within 50 psi (3.5 kg/cm 2 ) of each other, go to step 7). PRESSURE SPECIFICATIONS Application psi (kg/cm 2 ) All Models More Than 1000 (70)
  6. Flow control valve is sticking. Remove valve but DO NOT disassemble. Clean valve using crocus cloth or fine hone. Flush system if dirty. Install valve. Recheck pressure. If readings are now as specified, go to step 8).
  7. Replace flow control valve and retest system. If pressure readings are still low, check pump rotor and vanes for wear. Replace complete pump assembly if worn.
  8. With valve open, turn steering wheel from stop to stop. Record highest pressure with wheels at both stops. If highest pressure is not equal to highest pressure recorded in step 5), rack and pinion assembly is leaking internally. Repair or replace assembly. If pressures are equal, no problem exists. Go to next step.
  9. Turn engine off. Remove tester. Reconnect high pressure hose to pump. Check fluid level. Bleed hydraulic system. Refer to «HYDRAULIC SYSTEM BLEEDING»(/chevrolet/lumina/i-1989-2001/remont/electronic-steering/#steering-system-variable-effort__hydraulic-system-bleeding) under LUBRICATION.

FLOW RATE TEST

  1. Connect Power Steering Analyzer (J-25323-A) into system. Fully open analyzer valve. Run engine until fluid reaches operating temperature. Check fluid level. Add fluid if necessary. Record pressure and flow rate.
  2. Close valve partially until pressure is 700 psi (49.2 kg/cm 2 ), and then record flow rate. Subtract flow rate from that measured in step 1). If flow rate drops more than one gallon (3.8L) per minute, replace ring, rotor and vanes in pump. If not, go to next step.
  3. Increase engine speed to 1500 RPM, and record flow rate. Subtract flow rate from that measured in step 1). If difference between flow rates is more than one gallon (3.8L) per minute, remove and clean flow control valve. If not, go to next step.
  4. Turn steering wheel from stop to stop. Flow rate should be less than one gallon (3.8L) per minute at each stop. If flow rate is not as specified, check rack and pinion assembly for leakage.
  5. Turn engine off. Remove tester. Reconnect high pressure hose to pump. Check fluid level. Bleed hydraulic system. Refer to «HYDRAULIC SYSTEM BLEEDING»(/chevrolet/lumina/i-1989-2001/remont/electronic-steering/#steering-system-variable-effort__hydraulic-system-bleeding) under LUBRICATION.

TESTING - ELECTRONIC

Electronic testing information not available. Refer to the Wiring Schemtic for references to appropriate circuits. (Scheme 1)

Variable Effort Steering Schematic ("W" Bodies). Scheme 1

Scheme 1: Variable Effort Steering Schematic ("W" Bodies)
Scheme 1: Variable Effort Steering Schematic ("W" Bodies)

FLUID TYPE

Use GM Power Steering Fluid (1050017) or an equivalent meeting GM Specification No. 9985010. Failure to use proper fluid will cause hose and seal damage, resulting in fluid leaks and damage to pump and/or rack and pinion assembly .

CAPACITY

ApplicationPump: Pts. (L)System: Pts. (L)
All Models1.0 (0.5)1.5 (0.75)

POWER STEERING FLUID CAPACITY

FLUID LEVEL CHECK

Fluid level is indicated by marks on reservoir or dipstick. Ensure fluid level is at FULL COLD mark when fluid temperature is about 70°F (21°C). Ensure fluid level is at FULL HOT mark when fluid is at operating temperature of about 170°F (77°C).

HYDRAULIC SYSTEM BLEEDING

Note. If air is introduced into hydraulic system during servicing, bleed system. Aerated fluid, which appears Light Tan in color, results in poor steering performance and may cause pump damage.

  1. Turn ignition off. Raise and support vehicle with wheels off ground. Turn wheels fully to left. Add power steering fluid to FULL COLD mark on dipstick. Leave cap off. Turn wheels from side to side several times, but DO NOT touch steering stops. Add fluid, if necessary, to maintain level at FULL COLD mark.
  2. Start engine. With engine idling, recheck fluid level. Add fluid, if necessary, to bring level to FULL COLD mark. Install Cap. Return wheels to center position. Lower vehicle. Continue to run engine for 2-3 minutes.
  3. Road test vehicle. Check for leaks. Ensure fluid level is at FULL HOT mark when fluid stabilizes at operating temperature.

POWER STEERING PUMP BELT (SERPENTINE BELT)

  1. Serpentine belt tension is maintained by automatic tensioner. Ensure tensioner indicator mark on movable portion of tensioner is within limits of slotted area on stationary portion of tensioner. Any reading outside these limits indicates a worn belt or defective tensioner.
  2. If installing NEW belt, ensure tensioner indicator is within limit marks. If not, replace defective tensioner.
  3. If installing original belt, ensure belt's operating length and/or tensioner's operating range marks are not out of limits. Replace belt or tensioner as necessary.

RACK BEARING PRELOAD

  1. Raise and support vehicle. Turn front wheels to straight-ahead position. Loosen adjuster plug lock nut. (Scheme 2) Turn adjuster plug clockwise until it bottoms in housing. Back off adjuster plug 50-70 degrees (about one flat).
  2. While holding adjuster plug stationary, tighten adjuster plug lock nut to 50 Ft. Lbs (68 N.m). Test drive vehicle, ensuring steering wheel returns to center after turning.

Scheme 2

Scheme 2
Scheme 2