Steering System - Power Audi A6 C4

DESCRIPTION & OPERATION

A6 is equipped with detachable tie rods. With Servotronic, the degree of power assist from the steering is controlled electronically according to the vehicle speed. If there is a malfunction in the Servotronic system, the power steering system will continue to operate. A malfunction in the system may be noticed when maneuvering the vehicle and greater steering force that usual has to be used. If the steering requires greater effort on one side only, there is a hydraulic malfunction. Replace the steering gear to eliminate the problem.

HYDRAULIC SYSTEM INSPECTION

Ensure fluid level is sufficient. See FLUID LEVEL CHECK under LUBRICATION. Check power steering pump belt condition. Ensure hoses are not kinked or leaking.

POWER STEERING PUMP TEST

1. Install hose clamps, Snap-On(c) Model YA2850 or equivalent, on suction and pressure hoses. Press spring clamp and disconnect harness connector from fuel injector. Tightly hold hex fitting on flexible pressure hose, and disconnect threaded connection.
2. Install adapter US 1074/4C in the line in place of pressure hose. Install hose pressure gauge US 1074 on adapter US 1074/4C. (Scheme 1) Close locking valve of gauge. Install connector on fuel injector. Remove hose clamps from suction and pressure hoses.
3. Start engine. At idle, read pump pressure on gauge. Pressure should be 1740-1885 psi (120-130 bar). Stop engine. If pump pressure is not within specification, replace pump. See «POWER STEERING PUMP»(/audi/a6/c4-1994-1997/remont/manual-power-steering/#steering-system-power) under REMOVAL & INSTALLATION.
4. Install hose clamp on suction and pressure hose. Disconnect harness connector from fuel injector. Remove pressure gauge hose from adapter and put gauge aside. Take adapter off pressure line. Connect pressure hose to line by holding pressure hose hex. Install connector for fuel injector. Remove hose clamps from pressure and suction hoses. Let engine idle for approximately 2 minutes with front wheels pointed straight ahead.
5. Stop engine and immediately check power steering fluid level, noting marks on reservoir or dipstick. If necessary, top of to MAX mark. Check steering system for leaks.

Scheme 1

CAPACITY

Fluid capacity is about 1.2 Qts. (1.2 L).

FLUID TYPE

Recommended fluid type is Hydraulic Oil or Power Steering Fluid No. G 002 000.

FLUID LEVEL CHECK

Note. DO NOT re-use drained hydraulic fluid.

With front wheels in straight-ahead position, run engine at idle for 2 minutes. Stop engine (switch off ignition) and remove cap with dipstick. Fluid level should be top to MAX marking on reservoir and/or dipstick.

STEERING SYSTEM BLEEDING

1. Fill power steering fluid to MAX. With vehicle raised and engine NOT running, turn steering wheel forcefully from one stop to the other so air can escape from system.
2. Fill power steering fluid to MAX. With front wheel straight, let engine idle for 2 minutes. Note fluid level. As soon as no more bubbles rise in reservoir, stop engine and immediately fill power steering reservoir with fluid.

POWER STEERING BELT

Power steering belt tensioner is self adjusting.

STEERING PLAY

Note. Two technicians are required for the adjustment.

1. Ensure engine is not running, vehicle is resting on its wheels, and wheels are facing straight ahead.
2. Move steering wheel back and forth (approximately 30° around center axis) and listen for knocking noise inside vehicle.
3. Second technician turn adjusting bolt far enough inward so that knocking noise is no longer heard inside vehicle.
4. Turn adjusting bolt inward about 45° or 1/8-turn farther.
5. Road test vehicle.
6. If steering does not return to straight-ahead position automatically, turn adjusting screw back outward by approximately 15° and road test again.

REMOVAL & INSTALLATION

To idenify power steering pump components (Scheme 2)- (Scheme 5).

Scheme 2

Scheme 3

Scheme 4

Scheme 5

POWER STEERING PUMP BELT

1. Remove ignition coils with bracket. Remove upper pulley guard.
2. Turn open-end wrench in clockwise direction and install drift 3204.
3. Remove ribbed belt from pulley.

POWER STEERING GEAR

Removal

For removal procedures (Scheme 6)- (Scheme 11).

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Installation

Installation is the reverse of removal, with the following additional procedures

1. Install carrier in steering gear boot and fasten with both bolts.
2. Install steering gear through opening in right wheel housing (two technicians required).
3. Ensure correct routing of wiring harness. Install cable tie.
4. Carefully install instrument panel seal.
5. Fasten steering gear on left and right wheel housing.
6. Install left-side ABS wheel speed sensor mounting bracket and clip on sensor connector.
7. Remove left bolt from carrier fro tie rod mounting.
8. Install left tie rod in carrier and loosely thread in mounting bolt.
9. Remove right tie rod from carrier.
10. Install right tie rod in carrier and loosely thread in mounting bolt.
11. With vehicle resting on wheels, tighten both mounting bolts to specified torque. See «TORQUE SPECIFICATIONS»(/audi/a6/c4-1994-1997/remont/manual-power-steering/#steering-system-power__torque-specifications) .
12. Ensure correct sear of carrier in steering gear boot.
13. Fasten return and pressure hoses on rotary slide valve housing so hoses do not touch at any point.
14. Remove hose clamps (Snap-On(c) YA2850 or equivalent) from power steering return and pressure hose.
15. Carefully place sound insulation mats under pedals.
16. Install brake lines according to marking on ABS hydraulic unit.
17. Install brake lines and fuel line in brackets.
18. Bleed brake hydraulic system and check for leaks.
19. Ensure correct position of steering wheel.
20. Connect negative battery cable.
21. Check and/or top off power steering fluid. Check return and pressure hoses on rotary slide valve housing for leaks.

Note. Installation of tie rods is the reverse of removal procedures.

Scheme 12

Scheme 13

OVERHAUL

Note. Manufacturer recommends that power steering pump be replaced when overhauling steering gear..

Scheme 14

Scheme 15

Scheme 16

Scheme 17

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Electronic Power Steering System Wiring Diagram. Scheme 18

See also:
• FLUID LEVEL CHECK
• POWER STEERING PUMP
• TORQUE SPECIFICATIONS