Air Suspension Strut, Suspension
Air Suspension Strut, Suspension
• Boot must also be replaced when air spring is replaced.
• Observe repair notes for servicing suspension struts (air suspension). Refer to => [ Air Suspension Strut ] Rear Suspension.
Special tools, testers and auxiliary items required
• Torque Wrench 50-200 Nm (V.A.G 1332)
• Shock Absorber Set (T10001)
• Lithium grease
- Remove suspension strut (air suspension). Refer to => [ Air Suspension Strut ] Air Suspension Strut.
• Check whether air spring is still filled with a residual pressure of 3 bar.
• Press with thumbs on air spring bead. The bead must demonstrate noticeable resistance.
• If great resistance is not noticed, air spring is not pressurized and it must be replaced together with the residual pressure retaining valve.
Suspension Strut (air suspension), Disassembling
- Clamp suspension strut (air suspension) at lower mount in a vise with protective clamps - A -.
Make sure mount is not damaged.
- Loosen bolts - arrows - alternately on mounting bracket until air escapes from air spring.
• Suspension strut (air suspension) has approximately 3 bar residual pressure. Therefore, always loosen bolts - arrows - only about one rotation until air escapes.
• During disassembly, loosen mounting bracket bolts with light tilting motions of air spring.
• When loosening bolts, do not bend over suspension strut (air suspension) under any circumstances. If bolts are removed so far that air no longer escapes, there is risk of damage from mounting bracket and bolts.
• Suspension strut (air suspension) must not be rotated when it is not pressurized. There is the danger that the boot inside the air spring could be damaged by kinking or folding.
- Remove mounting bracket - 1 - in direction of - arrow - from suspension strut (air suspension).
Mounting bracket - 1 - must be guided over residual pressure retaining valve - 2 -.
- Remove nut from bearing.
1. Commercially available ratchet
2. (T10001/14)
3. (T10001/11)
4. (T10001/3)
- Remove bearing from shock absorber.
- Remove boot securing clamp - arrow -.
- Slide boot down and have it secured by a 2nd technician.
- Grasp air spring rolling pistons - 1 - with both hands and slide them with light right/left rotation upward in direction of - arrow - from shock absorber.
The entire air spring must rotate with it.
• Make sure that rolling piston - 1 - does not slip down out of outer guide - 2 -.
• If the air spring is reused and air spring has slipped out of the outer guide, it must be slid in again by forming even circumferential folds on the rolling boot - arrows -.
- When replacing air spring, slide stop buffer - 1 - down out of air spring centering seat.
Stop buffer is reused.
- Remove boot from collar on shock absorber - arrow - and remove it from shock absorber.
- If the shock absorber is replaced, then cover cap - 1 - and nut - arrow - must be removed and then installed on the new shock absorber.
Suspension Strut (air suspension), Installing
- If the shock absorber was not replaced, gasket must be replaced - arrow -.
- Clean contact surfaces with a lint-free cloth.
• Even the smallest contaminants lead to air spring leakage.
- Lightly grease ring with lithium grease.
- Position boot - 2 - on shock absorber.
- Slide stop buffer - 1 - with smaller diameter down onto shock absorber.
- Cover boot over shock absorber collar so that the collar engages in groove on boot - arrow -.
- Slide boot down and have it secured by a 2nd technician.
• If air spring is reused and air spring has slipped out of outer guide, it must be slid in again by forming even circumferential folds on the rolling boot - arrows -.
- Remove transportation protection from air spring.
- Position air spring on shock absorber and slide it onto shock absorber collar as far as stop. Grasp air spring rolling pistons - item 5 - => [ (Item 5) Rolling Piston ] Air Suspension Strut Components with both hands and slide it down with light right/left rotations.
- Position bearing and secure with a new nut.
1. Commercially available ratchet
2. (T10001/14)
3. (T10001/11)
4. (T10001/3)
- Clean contact surfaces on mounting bracket and air spring with a lint-free cloth.
• Even the smallest contaminants lead to air spring leakage.
- Replace gasket - arrow - and lightly grease it with lithium grease.
- Align air spring so that residual pressure retaining valve - 1 - is located near imaginary symmetrical axis - arrow - on suspension strut (air suspension).
• Only rotate at rolling piston - item 5 - => [ (Item 5) Rolling Piston ] Air Suspension Strut Components when doing so, in order to avoid damaging boot inside air spring.
- Residual pressure retaining valve - 1 - points in opposite direction of rear dampening adjustment valve - 2 -.
- Slide boot onto air spring and secure with a new clamp.
- Position mounting bracket and secure air spring with bolts - arrows -. Counter-hold at mounting bracket when doing so to prevent boot from rotating.
- Fill suspension strut (air suspension). Refer to => [ Air Suspension Strut, Filling ] Rear Suspension.
Mounting bracket must be installed so that upper bearing arm - 2 - points to residual pressure retaining valve - 1 -.
- Align air spring again so that residual pressure retaining valve - 1 - is located near imaginary symmetrical axis - arrow - on suspension strut (air suspension).
- Residual pressure retaining valve - 1 - points in opposite direction of rear dampening adjustment valve - 2 -.
- Submerge suspension strut (air suspension) completely in a water bath to check for leaks.
If there are no bubbles in the water, suspension strut (air suspension) does not leak and can be reinstalled in the vehicle.
If bubbles form in water from suspension strut (air suspension), it must be disassembled again and gaskets must be replaced.
• Before installing suspension strut (air suspension), blow out all connectors and residual pressure retaining valve with compressed air to dry them.
Tightening specifications, refer to => [ Air Suspension Strut Overview ] Rear Axle Overview