1996-1999 Mercedes-Benz S420 Rear Conversion Kit Installation Manual

Take a look at our easy-to-follow 1996-1999 Mercedes-Benz S420 Rear Conversion Kit Installation Manual to learn how to install your new Strutmasters air suspension conversion kit. Our step-by-step instructions include pictures to help you along the way.

Mercedes-Benz S420 parts included in this kit:

  • 2 Coil Springs and 2 Gas/Hydraulic Shocks.

Getting Started

  1. Read general service precautions
  2. Wear Eye Protection
  3. Support the vehicle
  4. Remove air suspension parts
  5. Install conversion kit

Tools needed for installation:

  • Metric socket set
  • Floor Jack
  • Jack Stands
  • Metric Wrench Set
  • Wire Cutter/Stripper/Crimping Tool
  • Level Work Surface
  • Spring Compressor (If Applicable)
  • Allen Wrenches
  • Screw Drivers (Phillips and Flat-Head)

Rear Suspension Removal and Rear Conversion Kit Installation InstructionsStep 1

Caution: A sudden release of pressure may cause personal injury or damage to the vehicle. The air suspension system is under pressure until the air supply lines are disconnected. Use the following precautions when servicing the air suspension system: Wear gloves, ear protection, and eye protection. Wrap a clean cloth around the air supply lines. The vehicle must be raised to perform this conversion! Use proper lifting equipment only! Read instructions carefully before attempting installation, if you have problems during the install then feel free to call our Technical Support Line. Please before calling for technical help, have your invoice handy.

If you have an Active Hydraulic Suspension System, you must cap/plug the lines. We are not responsible for damaged steering pumps.

  1. Raise the vehicle and remove the wheels. Support the vehicle by the frame so that there is no load on the suspension, see Fig 1.
  2. Disconnect the lever controller linkage, see Fig 2.
  3. Connect a drain hose to bleeder valve on the lever controller, see Fig 3.
  4. Pull down on the level controller arms. Slowly open bleeder valve on the level controller to bleed the pressure from the system. Close the bleeder valve, see Fig 4.
  5. Pull back or remove the trunk lining to access the upper shock mounting.
  6. Remove the nut and rubber insulator from the upper shock mount. The vehicle's wheel must be on the ground when this is done.
  7. Raise and support vehicle, see Fig 5.
  8. Remove the lower suspension arm cover, see Fig 6.
  9. Remove the lower shock mounting bolt, see Fig 7.
  10. Remove the hydraulic line running from the accumulator to the shock absorber (Make sure that you have bled any hydraulic pressure using the procedure described above before removing these lines), see Fig 8.
  11. Plug line, see Fig 9.
  12. Compress the spring (with spring outside of the vehicle), see Fig 10. Do not install yet.
  13. Support lower control arm with jack or jack stand. Remove sway bar from upper end link. Remove lower control arm outer bolt, loosen the inner bolt for control arm to pivot. Pivot the lower control arm downward and remove spring, see Fig 11.
  14. Install bolt and large washer through the bottom of lower control arm, see Fig 12.
  15. Install the locating puck with lock washer and nut, see Fig 13. Tighten nut.
  16. Install the spring isolator as shown. The original upper isolator will need to be reused on the top position, see Fig 14.
  17. Install the spring with the flat ground side towards the top, see Fig 15.
  18. Install a spring compressor and the new springs. Place the spring flat side up, using the original upper isolator position into car then pivot the lower control arm back into place. Secure the lower control arm with the original bolt, see Fig 16.
  19. Install shock, and then reassemble in the reverse order, see Fig 17.
  20. Secure the level controller arm in the center position, see Fig 18./li>
  21. Replace the lower suspension arm cover, see Fig 19.
  22. Start the vehicle and check for hydraulic fluid leaks. Check hydraulic fluid and top off if needed.

Conversion Kit installation now complete.

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