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Removing and installing hydraulic unit (hydraulic pump) > < Block diagram of hydraulic system operation

A4 Cabriolet Mk2

Filling and bleeding hydraulic system
Filling and bleeding hydraulic system
  Note
t  The electrohydraulic convertible top actuator mechanism is a closed hydraulic system. Filling is generally only required following loss of fluid (accident, leakage etc.).
t  On account of the stroke and displacement effect of the pistons in the hydraulic cylinders, the hydraulic system must be filled with the convertible top stowed in its compartment.
t  For this purpose, the convertible top must be moved with the electrohydraulic actuator mechanism.
  Caution
System is never to be filled beyond “MAX” mark, as otherwise pressure in system could become so great that damage might occur.
   
Filling
–  Remove the luggage compartment trim → Rep. Gr.70.
–  Screw out the oil filler plug -arrow-.
–  Use a can to add hydraulic fluid -G 004 000- until the fluid level is between the “MIN” and “MAX” marks.
Bleeding
  Note
The hydraulic system is bled automatically. Opening and closing the convertible top several times bleeds the system.
–  Start engine.
–  Close and open the convertible top 4 - 5 times by way of the electrohydraulic actuator mechanism.
l  Convertible top must move evenly and smoothly.
–  Check fluid level in reservoir -2- with convertible top stowed in its compartment.
l  Fluid level must be between “MIN ” and “MAX” marks.
–  Replenish the hydraulic fluid if necessary.
Tightening torques → Chapter
  A61-0237

Removing and installing hydraulic unit (hydraulic pump) > < Block diagram of hydraulic system operation