Convertible Top Hydraulic Control Unit: Service and Repair

54 34 005 Removing And Installing/Replacing Hydraulic Unit For Convertible Top Drive Unit (Z3 Roadster, M Roadster)

NOTE: Observe notes on EH convertible top. Procedures

Necessary preliminary tasks:
- Remove luggage compartment trim on left.
- Open emergency valve (system is depressurized)
- Lay an absorbent protective cover on the trunk floor next to the hydraulic control unit (danger of becoming running out).







NOTE: There are 2 different hydraulic units. The unit illustrated is the newer one. It was introduced at the beginning of 1999. In the event of replacement, this new unit can be installed.

Components:
1 Plug
2 Nut for cable
3AZ Hydraulic unit to body or carrier 10 Nm
3 Cable
4 Nut for mounting bracket
3AZ Hydraulic unit to body or carrier 10 Nm
5 Hydraulic unit with marking for fluid level
6 Relay with holder
7 Emergency valve
8 Oil filler plug
5AZ Oil filler plug to hydraulic unit 11 Nm

As both hydraulic units are very similar, the following text describes removal of the older unit:







- Disconnect plug (1)
- Release nut (2) and detach cable (3)
- Release nut (4)
- Unscrew hydraulic unit (5) inwards and set down on protective cover

Installation:
3AZ Hydraulic unit to body or carrier 10 Nm







Press down lock (1) and detach relay holder (2).







NOTE: Have a cloth ready to wipe away escaping oil.

If necessary, press relay holder to one side slightly.
Release banjo bolts (1) and (2) and remove lines.

Installation:
- Hose with red hose lettering (3) on hydraulic unit connection "red"
- Hose with blue hose lettering (4) on hydraulic unit connection "blue"
- 4AZ Lines to hydraulic unit 16 Nm

NOTE: If hydraulic components are to be stored for an extended period, seal off bores on hydraulic unit and hose connections for hydraulic cylinder.

Installation:







Always fit new banjo bolts (1) and seals (2 and 4) (sourcing reference: BMW Parts Service).

Banjo bolts (1) on hydraulic unit have a nozzle.

1 Banjo bolt
2 Upper seal (thin)
3 Hose connection
4 Lower seal (thick)

IMPORTANT: Check fluid level, top up if necessary.

Seal off lines and line connections:







Plug connections on hydraulic control unit:
Use the plugs (1) from the "Banjo bolts for hydraulic unit" set (sourcing reference: BMW Parts Service) and the old seals for this purpose.







Plug hose connections for hydraulic cylinder:
Use the plugs (1) and cap nuts (2) from the "Banjo bolts for hydraulic unit" set (sourcing reference: BMW Parts Service) and the old seals for this purpose.