Overhaul

Air Spring Damper

• Servicing the air spring damper for the time being only involves replacing the boot and cleaning the piston.






1 Clamp

• Mark the installed position of the connecting tube and the clips on the air spring damper before removing.

• Always replace if removed.

• Tensioning, refer to => [ Tighten the Clamping Sleeve on the Air Spring Damper ].

2 Boot

• Must not have any pressure marks; correct any pressure marks by hand.

• Push upward over the collars on the suspension strut housing.

3 Rolling Piston

• Clean if dirty.

• Visual inspection, refer to => [ Visual Inspection ].

4 Rubber Boot

• The surface must be regular and uniform.

• Visual inspection, refer to => [ Visual Inspection ].

5 Connecting Piece for the Air Line with the Residual Pressure Retaining Valve

• Tightening specification for the connector: 3 Nm

• Do not loosen the residual pressure retaining valve otherwise the air spring damper will get damaged.

6 Electrical Wiring

• To the left front damping adjustment valve (N336) or right front damping adjustment valve (N337).

7 Air Spring Shock Absorber

• If the left front dampening adjustment valve (N336) or right front dampening adjustment valve (N337) is faulty, the entire air spring damper must be replaced.

Special tools, testers and auxiliary items required

• Torque Wrench (V.A.G 1410)

• CV Joint Boot Clamp Tool (V.A.G 1682)

• Tensioning Strap (T10038)

Removing






• Replacement of boot is performed with air spring damper installed.

- Secure the wheel housing liner using a (T10038) - 1 -, as illustrated.

• To prevent the joints on the upper control arm from being damaged, support the wheel bearing housing.

- Remove shock absorber fork. Refer to => [ Shock Absorber Fork ] Front Suspension.

- Unclip the wires from the wire holder - arrow - and free them up.






- Remove the bolt - arrow - and remove the bracket - 1 - brake line and electric wires from the wheel bearing housing.






- Mark the position of the connection - 1 - and of the wire holder - 2 and 3 - with a felt-tip pen.






- Remove clamp - 1 -.

- Remove the boot - 4 - carefully off the collar on the suspension strut housing and then pull it down off the rolling piston and off the air spring damper.

Visual Inspection





• Check the surface of the rolling piston and the rubber boot for damage and dirt before installing.

- Check the rubber boot - 1 - for damage. The surface must be regular and uniform.

- Replace the air spring damper if damaged.

- Check the rolling piston - 2 - for damage and dirt and clean with surface with sand paper if necessary. Be careful not to make any grooves or scrapes.

Installing

Installation is the reverse of removal, with special attention to the following:

- Install the new boot carefully over the collar on the bottom of the rolling piston.

- Install shock absorber fork. Refer to => [ Shock Absorber Fork ] Front Suspension.

- Lift wheel bearing in control position. Refer to => [ Wheel Bearing, with Air Suspension, Lifting to Curb Weight Position ] Wheel Bearing, With Air Suspension, Lifting to Curb Weight Position.

- Push the boot - 4 - over the collar on the top of the suspension strut housing.






- Push the front wire holder - 2 - onto the clamp - 1 -.

- Install clamp - 1 - only loosely.






- Line up the clamp - 1 - with only one wire holder so that the connection - 3 - is in line with the marking made earlier on the rear wire holder.

- Align the front wire holder with the marking.

- Before tensioning clamps, make sure boot is not twisted, adjust if necessary.

- Tighten the clamp with (V.A.G 1682).

Tighten the Clamping Sleeve on the Air Spring Damper





- Use (V.A.G 1682) as shown in illustration. When doing that, make sure the jaws on the pliers are centered - arrow A - on the clamping sleeve.

- Tighten the clamp by turning the spindle using a torque wrench (do not tilt the pliers).

• Tightening specifications: 8 Nm

• Use torque wrench with 4 to 20 Nm range (for example (V.A.G 1410) ).

• Make sure the spindle threads on the pliers - A - move freely. Grease with MoS2 grease if necessary.

• If the thread is tight for example dirty, the required tensioning force for the hose clamp will not be achieved in spite of correct tightening specification settings.

- Tighten the loose threaded connections.