Hydraulic System, Filling And Bleeding

WARNING: This page is about a different car, the 2022 Audi S4, 2022 Audi A4 Quattro, 2021 Audi S4, and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

The following components must be replaced after removal. Refer to OVERVIEW - HYDRAULIC PUMP .

The electro-hydraulic convertible top operation involves a closed hydraulic system. Generally, filling is necessary after a loss of oil (accident, leaks, etc.). The hydraulic system must be filled when the convertible top is open and the convertible top compartment cover is closed due to the lift and displacement effects in the hydraulic cylinders.

Filling

-- Lift the luggage compartment floor.

-- Remove the storage compartment for the wind deflector.

-- Remove the lock carrier trim panel. Refer to LOCK CARRIER TRIM PANEL, REMOVING AND INSTALLING .

-- Remove the tool box -4-.

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-- Place the hydraulic pump -3- with the attached lines toward the rear.

-- Remove the adhesive strip -2-.

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-- Remove the noise insulation -1-.

-- Remove the hydraulic pump -4- from the noise insulation -3-.

Follow the guidelines for clean working conditions. Refer to GUIDELINES FOR CLEAN WORKING CONDITIONS .

-- Remove the oil filler plug -arrow-.

Fig 1: Locating Oil Filler Plug

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The hydraulic fluid reservoir must not be filled over the "+" marking.

CAUTION:

Risk of damaging to and malfunction of the hydraulic system by using hydraulic fluid which is not approved.

- Only use the vehicle-specific hydraulic fluid available through the Parts Information.

-- Fill the hydraulic fluid up to the "+" mark -arrow-. Hydraulic fluid. Refer to the Parts Information.

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Bleeding

TIP:

Hydraulic system is self-bleeding. The system is bled after opening and closing the convertible top several times.

-- Insert the old oil filler plug with a seal and tighten to the tightening specification.

Fig 2: Locating Oil Filler Plug

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-- Start the engine.

-- Open the convertible top with the electro-hydraulic actuator five times and stop in different positions.

The convertible top must move smoothly and without jerking.

-- Check the oil level in the reservoir -1- with the convertible top opened and the convertible top compartment cover closed.

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The oil level must be within the "+" - marking -arrow-. At the same time the hydraulic pump must be horizontal.

-- Replace the oil filler plug for the reservoir.

Tightening Specifications

Refer to OVERVIEW - HYDRAULIC PUMP