Self Leveling Suspension — Audi A8 D3 (2002-2005)

Contact corrosion!

Contact corrosion can occur if non-approved fasteners are used (bolts, nuts, washers etc.).

For this reason the manufacturer installs only fasteners with a special surface coating (Dachromet). These parts can be identified by their greenish color.

Moreover, both rubber and plastic parts as well as adhesives are made of materials which are not electrically conductive.

If you are not sure whether used parts can be re-installed, always install new parts.

Note. Always use genuine service replacement parts. These have been tested and are compatible with aluminum. Accessories must be approved by AUDI AG. Damage caused by contact corrosion is not covered by the warranty.

The system is bled automatically while driving.

The self-leveling suspension is adjusted by way of an adjustable-length connecting link between the level control valve and a lever attached to the stabilizer bar of the rear axle. See SELF-LEVELING SUSPENSION, ADJUSTING .

Counterhold the corresponding components when tightening hydraulic connections.

When fluid circuit has been opened always

Check all unions for leaks, start engine and perform visual inspections.
Check hydraulic fluid level with unladen vehicle, top off fluid if necessary. See «CHECKING OIL LEVEL, BLEEDING STEERING SYSTEM AND CHECKING FOR LEAKS»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering) .

Note. Items -1- to -21- apply to 6- and 8- cylinder-engines.

Note. Items 1 to 37 in the following list are illustrated in (Scheme 1).

Scheme 1

Scheme 2

Scheme 3

Filler cap with dipstick
Strainer for reservoir Use solvent to clean
Reservoir Re-fill with hydraulic fluid, Part No. G 002 000, capacity: 3 liters Plugged into hydraulic unit bracket Checking hydraulic fluid level on unladen vehicle. See «CHECKING OIL LEVEL, BLEEDING STEERING SYSTEM AND CHECKING FOR LEAKS»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering).
Clamp Always replace Tightening. See «TIGHTENING CLAMP WITH VAG 1275»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering). Can also be replaced by screw-type hose clamp
Clamp Always replace Tightening. See «TIGHTENING CLAMP WITH VAG 1275»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering). Can also be replaced by screw-type hose clamp
Clamp Always replace Tightening. See «TIGHTENING CLAMP WITH VAG 1275»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering). Can also be replaced by screw-type hose clamp
Return line Screwed into Item 13: 10 Nm (7 ft lb)
Return line Fluid cooler to connector
Return line Steering box to fluid cooler
Pressure line, 15 Nm (11 ft lb)
Return line, 15 Nm (11 ft lb)
Pressure line, 15 Nm (11 ft lb)
Return line, 15 Nm (11 ft lb)
Hex nut, 10 Nm (7 ft lb)
Retaining washer
Clamp
Bonded rubber bushing
Nut with washer, 25 Nm (18 ft lb)
Bracket
Bolt with washer, 8 Nm (71 in lb)
Fluid cooler Bolted to radiator Two versions with different line routings. NOTE: items -22- to -37- only apply to 6-cylinder engines.
Bolt with washer, 8 Nm (71 in lb)
Expansion hose Piston pump to pressure line Installation instructions. See «INSTALLATION INSTRUCTIONS: HIGH-PRESSURE HOSE»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__installation-instructions-high-pressure-hose).
Suction hose Part section with line
Bolt with washer, 10 Nm (7 ft lb)
Bracket Bolted to cylinder head
Threaded connection, 50 Nm (37 ft lb)
Seal Always replace
Tandem pump, 6 cyl. engine Tandem pump consists of plunger and vane pump. Piston pump is assigned to self-leveling, vane pump to power-assisted steering
Suction hose Part section
Banjo bolt, 25 Nm (18 ft lb)
Seal Always replace
Seal Always replace
Banjo bolt, 50 Nm (37 ft lb)
Pipe, 40 Nm (30 ft lb) Screw to expansion hose; counterhold on hex of expansion hose. Secured to intake manifold by way of bolt with washer -Item 36
Bolt with washer, 8 Nm (71 in lb)
Expansion hose Combined hose/line assembly, routed to steering box NOTE: Items -38- to -47- only apply to 8-cylinder engines. NOTE: Items 1 to 21, and items 38 to 47 are illustrated in (Scheme 2).
Tandem pump, 8 cyl. engine Tandem pump consists of piston pump and vane pump. Piston pump is assigned to self-leveling, vane pump to power-assisted steering. Checking piston pump delivery. See «SELF-LEVELING SUSPENSION, CHECKING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension). Removing and installing. See «VANE PUMP, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering).
Seal Always replace
Banjo bolt, 50 Nm (37 ft lb)
Suction hose
Seal Always replace
Banjo bolt, 50 Nm (37 ft lb)
Expansion hose Leads to steering box
Seal Always replace
Banjo bolt, 25 Nm (18 ft lb)
Expansion hose Piston pump - pressure line Installation instructions. See «INSTRUCTIONS FOR ATTACHING HIGH-PRESSURE HOSE TO TANDEM PUMP»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__instructions-for-attaching-high-pressure-hose-to). NOTE: Items 48 to 78 are illustrated in (Scheme 3).
Hex bolt
Bracket Introduction of modified bracket as part of design enhancement Bracket is bolted to the trapezoidal link mount. An M12 x 1.5 x 95 bolt with washer, shim and self-locking nut are used for this purpose Tightening torque: 70 Nm (52 ft lb) plus additional 90° (1/4 turn)
Level control valve Checking function. See «CONTROL VALVE, CHECKING FUNCTION»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__control-valve-checking-function). Checking for leaks. See «CONTROL VALVE AND SPRING CYLINDER, CHECKING LEAKS»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__control-valve-and-spring-cylinder-checking).
Return line, 15 Nm (11 ft lb) Connection of level control valve to manifold -Item 67
Pressure line, 15 Nm (11 ft lb) Distribution piece -Item 55- joint/right rear longitudinal member
Return line, 15 Nm (11 ft lb) Disconnection point at left rear manifold. See «DISCONNECTION POINT AT LEFT REAR WHEEL HOUSING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__disconnection-point-at-left-rear-wheel).
Pressure line, 15 Nm (11 ft lb) Disconnection point at left rear level control valve. See «DISCONNECTION POINT AT LEFT REAR WHEEL HOUSING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__disconnection-point-at-left-rear-wheel).
Connector Pressure lines
Pressure line 15 Nm (11 ft lb) Connector -item 55- / connector -item 77
Pressure line 15 Nm (11 ft lb) Level control valve / connector -item 55
Hex bolt, 20 Nm (15 ft lb)
Washer
Hex bolt, 10 Nm (7 ft lb)
Seal Always replace
Seal Always replace
Banjo bolt, 25 Nm (18 ft lb)
Fluid return line, 15 Nm (11 ft lb) Manifold / disconnection point at left rear longitudinal member
Ring piece
Fluid return line, 15 Nm (11 ft lb) Manifold / disconnection point at right rear longitudinal member
Manifold Return line/fluid return lines
Washer
Hex nut, 10 Nm (7 ft lb) NOTE: Items -70- to -74- are in mirror-image arrangement on left and right of vehicle. Spring cylinder is removed with the pressure line -Item 71-. Loosen pressure line on right side of joint -Item 71- and -Item 52-. On the left side at disconnection point on left rear longitudinal member -Item 78-.
Return line Tighten to 15 Nm (11 ft lb) at disconnection point -item 66-. CAUTION: Tighten 10 Nm (7 ft lb) at rear wheel housing/spring cylinder disconnection point.
Pressure line 15 Nm (11 ft lb) Disconnection point at right rear longitudinal member / spring cylinder Note installation position at spring cylinder. See «INSTALLATION POSITION OF PRESSURE LINE AT SPRING CYLINDER»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension). Pressure line must be handled with care when removing spring cylinder. Do not bend.
Banjo bolt, 20 Nm (15 ft lb)
Sealing ring Always replace
Spring cylinder with pressure accumulator NOTE: The spring cylinder is removed with the pressure line -Item 71-. Removing and installing. See «SHOCK ABSORBER»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear). Check spring cylinder. See «CONTROL VALVE AND SPRING CYLINDER, CHECKING LEAKS»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__control-valve-and-spring-cylinder-checking). Check pressure accumulator. See «PRESSURE ACCUMULATOR, CHECKING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension__pressure-accumulator-checking).
Bracket
Bleed valve, 15 Nm (11 ft lb)
Connector
Pressure line 15 Nm (11 ft lb) Connector -item 77- / disconnection point at left rear longitudinal member NOTE: Items 79 to 89 are illustrated in (Scheme 4).
Hex bolt
Lever
Stabilizer bar
Rubber bushing
Clamp
Self-locking nut, 10 Nm (7 ft lb) Always replace
Direction of travel
Self-locking nut, 5 Nm (44 in lb) Always replace
Connecting link Adjustable length for adjusting self-leveling suspension: Loosen hex nut -arrow-, adjust connecting link length, tighten nut to 2 Nm (18 in lb).
Securing plate
Self-locking nut, 5 Nm (44 in lb) Always replace

Installation instructions: high-pressure hose

Applies to items 15 and 16 in SELF-LEVELING SUSPENSION, SERVICING, (Scheme 1).

The expansion hose should protrude 4 mm + 2 mm from clamp.

Instructions for attaching high-pressure hose to tandem pump

A = 25 Nm (18 in lb)

Scheme 4

Scheme 4: Instructions for attaching high-pressure hose to tandem pump

Disconnection point at left rear wheel housing

Pressure line
Return line
Brake line
Brake line

Scheme 5

Scheme 5: Installation position of pressure line at spring cylinder

Piston pump, checking delivery

Remove pressure line from pump.
Connect hose of pressure limiter -VAG 1354- to pump using original banjo bolt and metal seals, Part No. N 013 808 3.
Remove reservoir cap.
Insert end of pressure limiter -VAG 1354- line into reservoir.
Leave engine idle until line has been bled.
Switch off ignition and hold end of pressure limiter line over a graduated container.
Allow engine to idle. Specified delivery value: at least 0.2 liters per minute.
Replace tandem pump if specified value is not attained. See «POWER STEERING/FLUID CIRCUIT, ASSEMBLY OVERVIEW»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering) .
Switch off ignition.
Reconnect pressure line.
Check all unions for leaks, start engine and perform visual inspection.
Check hydraulic fluid level with vehicle unladen, top off fluid if necessary. See «CHECKING OIL LEVEL, BLEEDING STEERING SYSTEM AND CHECKING FOR LEAKS»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering) .

Control valve, checking function

Leave engine idling, vehicle must be standing on the ground.

Checking raising function

Load luggage compartment with approx. 150 kg (2 people).
Rear of vehicle must be raised (time required: up to approx. 2 minutes).

Checking lowering function

Remove load from luggage compartment.
Vehicle must be lowered again after weight is removed.

Control valve and spring cylinder, checking leaks

Note. Leak test is best performed on a lifting platform with ramp or over a pit.

Checking control valve and right spring cylinder

Remove dust cap from one of the bleed screws (-Item 76- in «SELF-LEVELING SUSPENSION, SERVICING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension), (Scheme 3) ).
Attach bleeder hose of pressure tester VAG 1354 to bleed screw.
Open bleeder screw, use suitable container to collect hydraulic fluid which emerges.
Tighten bleeder screw on connector.
Pull bleeder hose off bleed screw on connector and attach to bleeder screw of pressure tester.
Remove pressure line from connector (-Item 56- in «SELF-LEVELING SUSPENSION, SERVICING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension), (Scheme 3) ).
Connect pressure tester VAG 1354 to pressure line: 15 Nm (11 ft lb).
Load luggage compartment with approx. 150 kg.
Start engine and let idle.
Observe reading on pressure gauge, switch off ignition at approx. 50 bar (725 psi). Note gauge pressure.
Leave vehicle for roughly 3 hours.
Check reading on pressure gauge: Max. pressure drop 5 bar (72.5 psi).
If pressure drop exceeds 5 bar, either control valve or spring cylinder is leaking and should be replaced. Open disconnection point of -item 66- and -item 70- (see «SELF-LEVELING SUSPENSION, SERVICING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension), (Scheme 3) ). If more than 0.2 cl of fluid escapes at this location, replace the right spring cylinder. If no fluid escapes, replace the control valve.
Carefully open bleeder screw of pressure tester VAG 1354, catch hydraulic fluid emerging in suitable container. Pointer of pressure gauge will drop slowly. Remove pressure tester VAG 1354.

Checking control valve and left spring cylinder

With the exception of the following steps, this test is identical with that for the right side.
Open disconnection point of -items 52- and -item 71- (see «SELF-LEVELING SUSPENSION, SERVICING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension), (Scheme 3) ).
Connect pressure tester VAG 1354 to pressure line, 15 Nm (11 ft lb).
If pressure drop exceeds 5 bar (72.5 psi), either control valve or spring cylinder is leaking and should be replaced. Open disconnection point at rear longitudinal member. See -item 64- in «SELF-LEVELING SUSPENSION, SERVICING»(/audi/a8/d3-2002-2005/remont/electronic-suspension/#self-leveling-suspension), (Scheme 3). If more than 0.2 cl of fluid escapes at this location, replace the left spring cylinder. If no fluid escapes, replace the control valve. Carefully open bleeder screw of pressure tester VAG 1354, catch hydraulic fluid emerging in suitable container. Pointer of pressure gauge will drop slowly. Remove pressure tester VAG 1354.

Pressure accumulator, checking