Body - When Operating Vario Roof Trunk Lid Won't Close

Trunk lid fails to close when opening/closing the Vario roof

Topic number LI77.37-P-048796

Version 1

Design group 77.37 Vario roof, soft top - hydraulic components

Date 02-05-2010

Validity R230 & 171

Reason for change Model designation extended / Supersedes DTB P-B-77.
37/21

Reason for block

Complaint:

The trunk lid closes slowly or not at all when the Vario roof is opened or closed.

Cause:

Three possible causes:

- internal leakage on hydraulic cylinder at front of Vario roof (item 6)

- internal leakage on hydraulic cylinder at trunk lid latch (item 4/5)

- internal leakage on hydraulic cylinder at trunk lid actuator (item 3)

Attachments

Remedy:

Perform hydraulics test with special tool valve block, part no. 230 589 00 91 00:

1. Expose hydraulic unit, unplug connectors, unscrew nuts.

2. Reposition hydraulic unit so that the hydraulic lines are accessible, remove cable straps (A).

3. Release left connection plate and remove hydraulic lines 90, 92, 93, 94 on hydraulic unit.

4. Remove yellow stop plugs (B) from hydraulic line on valve block special tool and and use to seal connectors of detached hydraulic lines.

5. Connect first 4 hydraulic lines (C) from special tool valve block to hydraulic unit.

6. Connect hydraulic lines 90, 92, 93, 94 to special tool valve block in ascending numerical order.

7. Return hydraulic unit to its operating position, reconnect connectors and close trunk lid.

8. Operate Vario roof in the "Open" direction until the trunk lid is opened, then release the switch.

9. Close connection for line 94 on valve block with knurled screw.

10. Operate Vario roof in the "Open" direction.

If the trunk lid closes:

Important:
Release the switch just before it reaches the trunk lid latches otherwise the latches may be damaged by the tubular frame.

Observe this instruction in the subsequent test steps too.

11. See notes on replacing right hydraulic cylinder for trunk lid latch, see AR77.37-P-3540R.
If the trunk lid does not close:

Operate Vario roof in the "Close" direction until the Vario roof rests on the windshield cross member. Release the switch while the trunk lid is still open and when the side flaps are retracted.

Note:
With the roof in this position, the valve block in the trunk is accessible.

12. Reopen connection for line 94 on valve block and close connection for line 93 on valve block.

13. Operate Vario roof in the "Open" direction.

If the trunk lid closes:

14. See notes on replacing left hydraulic cylinder for trunk lid latch, see AR77.37-P-3540R.

If the trunk lid does not close:

15. Reopen connection for line 93 on valve block and close connection for line 90 on valve block.

16. Operate Vario roof in the "Open" direction.

If the trunk lid closes:

17. See notes on replacing hydraulic cylinder for front Vario roof latch, see AR77.37-P-3560R.

If the trunk lid does not close:

18. Reopen connection for line 90 on valve block

19. Operate Vario roof in the "Close" direction and get an assistant to simultaneously push the trunk lid closed by hand until the tubular frame latches engage and lock.

If the latches fail to lock:

Unlock trunk lid with emergency key, open it and lock the tubular frame latches with an Allen wrench.

20. Seal connections for lines 90, 92, 93, 94 on valve block using knurled screws, push to close and lock trunk lid.

21. Operate roll bar with convenience switch in the "Raise/Lower" direction.

If the roll bar cannot be raised:

Hydraulic unit OK. See notes on replacing hydraulic cylinder for trunk lid actuation, see AR77.37-P-3550R. If the roll bar cannot be retracted:

22. Replace hydraulic unit, AR77.37-P-3500R.