Removing and installing/replacing hydraulic unit (drive) for retractable hardtop (M4 Convertible)
Necessary preliminary tasks:
- Remove TRIM PANEL FOR LUGGAGE COMPARTMENT SIDE MEMBER on left and right
Attention:
Following removal of the lines, hydraulic fluid can emerge from the lines as well as from the open connection fittings on the hydraulic unit (drive).
Protect components and work area with suitable materials (e.g. cloths).
Do not fit hydraulic lines in kinked, crushed or transposed condition.
Unfasten screw connection (1).
Tightening torque 51 71 11AZ .
Remove the torsion strut (2).
Unlock and detach plug connections (1 and 2).
Carefully guide out control unit (1) to remove it as necessary.
Release cable strap (2).
Release retaining straps (3).
Unfasten plug connection (1) and disconnect.
Fold up sound insulation (2).
Release cable strap (3).
Use a hexagon socket (SW 4) to slowly open the shutoff valve (4) on the hydraulic unit by four turns.
The system is now de-pressurized.
Installation note:
After installation, check to confirm that the shutoff valve (4) is closed.
After a replacement the new hydraulic unit is delivered with the shutoff valve (4) open.
Open the shutoff valve (4). Then close it to ensure that the shutoff valve (4) is closed.
There may still be a low residual pressure in the hydraulic unit (1) tank.
Loosen oil filler plug (2) to compensate the pressure with the ambient pressure.
Tighten oil filler plug (2).
Mark the position of the plug connections (1 through 5).
Unlock and disconnect the plug connections (1 to 5).
Installation note:
Make sure the connectors have been correctly assigned to the valves.
Protect separation points from emerging hydraulic fluid, e.g. by using a cleaning cloth.
Disconnecting hydraulic lines from hydraulic unit:
- Loosen screws at latching tabs (1)
- Push open latching tabs (1)
- Pull off hydraulic lines by turning them slightly
- Secure latching tabs (1) using screws
- Remove the hydraulic unit (drive)
Installation note:
Hydraulic lines and connections are marked with numbers to prevent mix-ups.
Check FLUID LEVEL or top up if necessary.
Use only the approved hydraulic fluid: Aral Vitamol ZHM, BMW part number 54 34 0 394 395 (250 ml)
In case of motor vehicles with production date up until 11/15 , the integration level on the Body Domain Controller should be updated (I level F020-15-11-502 or higher)!
Carry out PROGRAMMING/ENCODING if necessary.