DESCRIPTION
The steering system consists of a belt-driven vane pump, rotary piston pinion gear assembly, and an oil reservoir. The flow control valve supplies fluid to the proper side of the rack piston when the steering wheel is turned. The pump mounts on the front of the engine. The reservoir is near the firewall.
SYSTEM PRESSURE TEST
- Connect Pressure Gauge (US1074/2 on Coupe GT, 4000S and 4000CS Quattro; US1070 on 5000S, 5000CS Turbo and 5000CS Quattro) between pressure hose and pressure pipe of valve housing, with pressure gauge valve open. Run engine at idle.
- Turn steering wheel lock-to-lock several times. Check pressure. Pressure should be 2103-2248 psi (148-158 kg/cm 2 ). If pressure is not within limits, replace steering gear.
PUMP PRESSURE TEST
- Install pressure gauge. Start engine and let it idle. Close gauge valve for a maximum of 5 seconds. Check pressure. Pressure should be 2103-2248 psi (148-158 kg/cm 2 ).
- If pressure is not within specification, inspect bores in valve and piston for obstructions. Check that piston moves freely in housing. Install new valve (if necessary).
LEAKAGE TEST
- With engine idling, turn steering wheel to full lock and hold. Inspect all connections. If leak shows at steering pinion, replace housing seal and both intermediate cover seals.
- If pinion shaft seal is leaking, fluid will have entered gear housing. Check for fluid by loosening outer clamp on right steering boot while pushing boot in. If seal is leaking, replace all seals.
FLUID CAPACITY
Lubricant capacity is 1 qt. (.95L).
FLUID TYPE
Recommended fluid is Audi Hydraulic Fluid (G 002 000).
FLUID LEVEL CHECK
Remove reservoir cover. Start engine. Check fluid level. Fluid level should be at mark on upper inside of reservoir neck.
HYDRAULIC SYSTEM BLEEDING
- With engine at idle, check that fluid is at proper level. Turn steering wheel lock-to-lock several times quickly. DO NOT force wheel against locks.
- Repeat step 1) until fluid level remains at reservoir mark. Ensure no bubbles appear in reservoir when steering wheel is turned. Shut off engine. Check that oil level does not rise more than .375" (10.00 mm) above mark inside of reservoir.
OIL FILTER REPLACEMENT
Remove outer cover, gasket, and spring from reservoir. Remove inner filter cover and filter insert. Install new filter insert. Replace old filter cover, spring, gasket, and top cover. Check fluid level.
Scheme 1
Note. Oil filter insert must be replaced whenever repairs are made to power steering system.
Scheme 2
5000 Series Steering Gear Adjustment No play should be felt. Courtesy of Audi of America, Inc. Scheme 3
PUMP BELT
Loosen pump-to-bracket mounting bolts. Turn adjusting nut on bracket until belt deflection is .375" (10 mm) at center of belt. Tighten bracket nuts.
STEERING GEAR
On 5000 series models, loosen lock nut on steering gear. Hand tighten adjusting screw until it touches thrust plate. Holding adjusting screw in position, tighten lock nut. Check adjustment with engine idling. Readjust (if necessary).
Removal (Coupe GT, 4000S & 4000CS Quattro)
- Drain fluid from system. Disconnect hydraulic lines from valve housing. Disconnect lower steering shaft from pinion shaft. Move cap out of the way.
- Remove steering drive pawl and tie rod bracket nuts. Disconnect tie rods from bracket. Remove bolts attaching gear housing to body. Remove housing.
Installation
To install, reverse removal procedure. Install one tie rod to steering gear and start bolts before installing other tie rod.
Removal (5000S, 5000CS Turbo & 5000CS Quattro)
- Drain fluid from system. Disconnect hydraulic lines. Cap openings. Remove tie rod lock plate and both tie rod retaining bolts.
- Separate tie rods from steering gear. Disconnect steering damper. Disconnect flange tube clamp from steering gear. Remove flange tube from steering shaft.
- Remove steering gear retaining bolts from body. Turn wheels to right lock. Remove steering gear through opening in right wheelwell.
To install, reverse removal procedure. Replace tie rod lock plate before reinstallation. Install one tie rod to steering gear before installing other tie rod.
Removal
Remove vane pump belt. Disconnect hydraulic lines from pump. Cover openings. Remove retaining bolts from bracket. Lift pump from engine.
To install, reverse removal procedure. Adjust belt deflection to .375" (10 mm) at center. After installing hydraulic lines, start engine. Turn steering wheel to full lock. Check for leaks.
OVERHAUL
Note. Overhaul of 5000 series models steering gear is not recommended. Seals can be replaced if gear is removed. Check system output and pressure before removing steering gear.
Note. On Coupe GT, 4000S and 4000CS Quattro models, check output and system pressure before disassembling steering gear. Use all parts in Repair Kit (811 498 020 ). Use new self-locking nuts.
Disassembly (Coupe GT, 4000S & 4000CS Quattro)
- Remove valve housing attaching bolts. Remove housing. Remove pinion gear and intermediate cover. Remove "O" rings from intermediate cover (one on each side). Clamp housing in padded vise. Drive out oil seal from the back.
- Install new "O" rings on intermediate cover. Install new seals in valve. Ensure housing seal lip faces intermediate cover. Replace intermediate cover "O" rings.
Reassembly
To reassemble, reverse disassembly procedure. Protect pinion teeth on shaft when replacing intermediate cover. DO NOT damage "O" rings.
Exploded View of Vane Pump Assembly Only pressure/flow limiting valve can be replaced. Courtesy of Audi of America, Inc. Scheme 4
Disassembly (5000S, 5000CS Turbo & 5000CS Quattro)
- Remove valve housing retaining bolts. Remove housing. Remove pinion gear and intermediate cover. Remove "O" rings from intermediate cover. Drive out intermediate cover oil seal.
- Clamp housing in padded vise. Drive out oil seal from the back. Install new seals from inside cover and housing. Ensure housing seal lip faces intermediate cover, and cover seal lip faces valve housing. Replace both intermediate cover "O" rings.
To Reassemble, reverse disassembly procedure. Protect pinion teeth on shaft when replacing intermediate cover. DO NOT damage "O" rings.
Scheme 5
- With steering gear removed from vehicle, remove pinion valve housing. Remove pinion valve assembly, plate, seal retainer, spring, and thrust piece from steering housing.
- Remove retaining ring, clamp and boot, retaining ring, and snap ring from housing. Remove end housing and "O" ring from housing. Pull rack from housing. Using oil seal puller, remove oil seal from housing.
- To install new oil seal in housing, place oil seal on flat surface and push sleeve (available in Repair Kit 811 498 020 ) into oil seal. Slide rack into housing.
- Using Seal Installers (VW 426 and VW 416b ), slide oil seal with sleeve over rack and into housing. Remove sleeve. Install snap ring and retaining ring into housing.
- Install end housing with new "O" ring. Install thrust piece, spring, "O" ring, seal retainer, and plate. Install clamp, boot, and retaining ring. Install valve assembly as previously outlined.
With steering gear removed from vehicle, drive out right end of steering housing with a drift. Remove seals and "O" ring. Clamp rack in a padded vise. Remove self-locking nut and piston. Insert Slide Hammer (VW771 ) into right side of housing. Remove oil seal and shims.
Using Driver (2082 ), install shims and seal with thin shim behind seal and seal lip facing piston. Install piston, self-locking nut, seals, "O" ring and end housing.
TORQUE SPECIFICATIONS
| Application | Ft. Lbs. (N.m) | |
|---|---|---|
| End Housing | 37 (50) | |
| Expansion Hose (1) | 29 (39) | |
| Flange Tube-to-Steering Gear (1) | 22 (30) | |
| Pinion Shaft Nut (1) | 14 (19) | |
| Pressure Pipe | 29 (39) | |
| Pulley-to-Pump Shaft (1) | 14 (19) | |
| Pump Retaining Bolts (1) | 14 (19) | |
| Return Pipe | ||
| On Pump | 29 (39) | |
| On Valve Housing | 22 (30) | |
| Steering Damper (1) | 29 (39) | |
| Tie Rod Locking Nut (1) | 43 (58) | |
| Tie Rod-to-Steering Gear (1) | 43 (58) | |
| Steering Housing Locking Nut (1) | 29 (39) | |
| Suction Hose (1) | 29 (39) | |
| Valve Housing Bolts (All Except 5000 Series) | 15 (20) | |
| INCH Lbs. (N.m) | ||
| Valve Housing Bolts (5000 Series) | 84 (10) | |
| (1) 5000 series only. | ||
| (1) | 5000 series only. |
TORQUE SPECIFICATIONS