Damper valves - Removal and installation - RA32001290680X(32-0680)

Preceding work:

Pressure oil system drained (32-0630) .

1. Front axle - Model 129 
   Fig 1: Identifying Damper Valves Remove/Install Components (Front Axle)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   Connectors (Y51x1, Y52x1)	disconnect, connect. Pull downwards out of the splash wall, install in splash wall with rubber grommet (No. 1). Version as of 7/93: Disconnect electrical lead from damper valve (Position 6).
   Front wheels	remove, remount. Torque lug bolts to 110 Nm.
   Cover in front wheel-housing	remove, install.
   High-pressure line (P4)	detach, reconnect at both ends. M16x1.5 = 30 Nm M18x1.5 = 44 Nm.
   Damper valves (Y51, Y52)	remove, install. Tightening torques for bolts: M6 = 10 Nm M8 = 20 Nm.

   NOTE: On vehicles manufactured from 7/93 onward, the connections (Y51x1, Y52x1) are plugged directly into the damper valve (in engine compartment on earlier versions).
   An adapter line is supplied with the damper valve in the standard package contents.

   Removal, installation 

   1. Detach connectors (Y51x1, Y52x1). Detach cable from the retaining clip and remove together with the rubber grommet downwards from the splash wall.

      Installation note 

      Ensure correct seating of rubber grommet.

      Fig 2: Identifying Connectors And Damper Valve (Front Axle, Left)

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
      Fig 3: Identifying Connectors And Damper Valve (Front Axle, Right)

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   2. Remove the front wheels.

      Installation note 

      Torque lug bolts to 110 Nm.

   3. Unscrew the five hexagon bolts (arrows).

      Remove guards (A and B) in wheel-housing.

      Fig 4: Identifying Five Hexagon Bolts And Guards

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   4. Disconnect the high-pressure line (P4) from the damper valve.

      Installation note 

      Tightening torques: M16x1.5 = 30 Nm

      M18x1.5 = 44 Nm.

   5. Screw off the bolts/nuts holding the damper valves (Y51, Y52) in place.
      Fig 5: Identifying High-Pressure Line And Damper Valve (Version Installed Up To 6/93)

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   6. Remove damper valves. Also detach electrical wire on versions manufactured from 7/93 onward.

      Installation notes 

      Tightening torques:

      M6 = 10 Nm

      M8 = 20 Nm.

      Fig 6: Identifying Damper Valve (Version Installed From 7/93)

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   7. Installation is in reverse sequence.
2. Rear axle - Model 129 
   Fig 7: Identifying Damper Valves Remove/Install Components (Rear Axle Model-129)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   Covers for spare tire and electrical wiring in luggage compartment	remove, install.
   Connectors (Y53x1, Y54x1)	disconnect, reconnect, remove, install at firewall with rubber grommet, version installed up to 6/93 (Position 2). Version installed from 7/93 onward: Disconnect the electric lead at the damper valve (Position 8).
   Vehicle	raise, lower.
   Cross member (69)	remove, install. Replace self-locking bolt (69b), 120 Nm.
   Rear muffler	remove, remount in rubber doughnuts, secure with hook.
   Pressure lines (P4)	disconnect, reconnect. Replace banjo bolt gaskets. Tightening torques: Banjo bolt = 50 Nm M16x1.5 = 30 Nm M18x1.5 = 44 Nm.
   Damper valves (Y53, Y54)	remove, install. Tightening torques: M6 = 10 Nm. M8 nut = 14 Nm M8 bolt = 24 Nm.

   NOTE: On vehicles manufactured from 7/93 onward, the connections (Y53x1, Y54x1) are plugged directly into the damper valve (in luggage compartment on earlier versions).

   An adapter line is supplied with the damper valve in the standard package contents.

   Removal, installation 

   1. Remove spare wheel and cable cover in luggage compartment.
   2. Remove the wire plugs (Y53x1, Y54x1) from the clips, disconnect the plugs. Remove the wire from its clip, then pull from the firewall together with the rubber grommet (versions installed up to 6/93).

      Installation note 

      Ensure that the rubber grommets seat properly.

      Fig 8: Identifying Wire Plugs

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   3. Raise vehicle.
   4. Unscrew self-locking bolt (69b) and remove cross strut (69).

      Installation note 

      Replace self-locking bolt (69b), 120 Nm.

      Fig 9: Identifying Self-Locking Bolt And Cross Strut

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   5. Detach rear muffler from the rubber rings and secure with hook.
   6. Unbolt pressure lines (P4) at the damper valves (Y53, Y54).
      Fig 10: Identifying Pressure Lines And Damper Valves

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

      Installation note 

      Replace the gaskets on the banjo bolt.

      Tightening torques:

      Banjo bolt = 50 Nm.

      High-pressure line M16x1.5 = 30 Nm,

      M18x1.5 = 44 Nm.

   7. Unscrew the bolts/nuts used to hold the damper valves (Y51, Y52) in place.
   8. Remove the damper valves. Also disconnect the wire from the damper valve on vehicles manufactured from 7/93 onward.
      Fig 11: Identifying Left Side Damper Valves

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

      Installation note 

      Tightening torques:

      M6 = 10 Nm.

      M8 nut = 14 Nm

      M8 bolt = 24 Nm.

      Fig 12: Identifying Damper Valves Right Side

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   9. Installation is in reverse sequence.
3. Rear axle - Model 140 
   Fig 13: Identifying Damper Valves Remove/Install Components (Rear Axle Model-140)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   Luggage compartment trim panels	remove, install.
   Wire plugs (Y53x1, Y54x1)	disconnect, reconnect, remove, install in firewall with rubber grommets. Versions installed up to 6/93 (Position 2). Versions installed from 7/93 onward: Disconnect the electrical wire at the damper valve.
   Vehicle	raise, lower.
   Rear muffler	remove, remount in rubber doughnuts, secure with hooks.
   High-pressure line (P4)	disconnect, reconnect on both sides. Torque specification: M16x1.5 = 30 Nm M18x1.5 = 44 Nm.
   Damper valves (Y53, Y54)	remove, install. Tightening torque: M8 nut = 14 Nm M8 bolt = 24 Nm.

   NOTE: On vehicles manufactured from 7/93 onward, the connections (Y53x1, Y54x1) are plugged directly into the damper valve (in luggage compartment on earlier versions).
   An adapter line is supplied with the damper valve in the standard package contents.

   Removal, installation 

   1. Remove left-hand luggage compartment lining.
   2. Remove the wire plugs (Y53x1, Y54x1) from the clips, disconnect the plugs. Remove the wire from its clip, then pull from the firewall together with the rubber grommet (versions installed up to 6/93).

      Installation note 

      Ensure that the rubber grommets seat properly.

   3. Raise vehicle.
      Fig 14: Identifying Wire Plugs

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   4. Remove the rear muffler form its rubber mounting doughnuts and secure with a hook.
   5. Disconnect the high-pressure lines (P4) from the damper valves (Y53, Y54).

      Installation note 

      Torque specification:

      High-pressure line M16x1.5 = 30 Nm,

      M18x1.5 = 44 Nm.

      Fig 15: Identifying High-Pressure Lines And Damper Valves (Right Side)

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   6. Unscrew the bolts/nuts used to hold the damper valves (Y53, Y54) in place.

      Remove the damper valves. Also disconnect the wire from the damper valve on vehicles manufactured from 7/93 onward.

      Installation note 

      Tightening torque:

      M8 nut = 14 Nm

      M8 bolt = 24 Nm.

      Fig 16: Identifying Damper Valves (Left Side)

      Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   7. Install in reverse sequence.