Heater Core, Removing And Installing: Removing

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Removing

-- Perform the preparation work for removing the heater core. Refer to HEATER CORE, PREPARING FOR REMOVAL .

-- Open the cap on the coolant expansion tank and release the pressure in the coolant system. Refer to COOLANT, DRAINING AND FILLING for 2.0L, COOLANT, DRAINING AND FILLING for 3.0L, or COOLANT, DRAINING AND FILLING for 3.2L .

-- Mark the arrangement of coolant hoses -A- (supply to cylinder head) and -B- (return to coolant pump).

Fig 1: Identifying Battery (+) Cable, Coolant Hoses And Plenum Chamber Grommet

Courtesy of AUDI OF AMERICA, LLC

NOTE:

The heater core is designed for a specific coolant flow direction. Therefore, coolant hoses must be connected on the correct sides.

Bleed the coolant circuit. Refer to COOLANT, DRAINING AND FILLING for 2.0L, COOLANT, DRAINING AND FILLING for 3.0L, or COOLANT, DRAINING AND FILLING for 3.2L .

-- Clamp the coolant hoses -A- and -B- with hose clamps.

-- Cover the area beneath connections for coolant hoses -A- and -B-, for example with absorbent paper.

-- Remove the coolant hoses -A- and -B- from the connections to the A/C heater core. Refer to COOLANT SYSTEM/COOLANT for 2.0L, or COOLANT SYSTEM/COOLANT for 3.2L .

-- Insert one section each of hose -A- and -B- on to both connections to heater core.

Fig 2: Using A Compressed Air Gun Carefully Blow Coolant Out Of Heater Core

Courtesy of AUDI OF AMERICA, LLC

-- Place a container -B- under the other end of the hose -C-.

-- Using a compressed air gun -D-, carefully blow coolant out of heater core (into container -B-) via hose -A-.

-- Remove the clamps -B- and -C- from the heater core connections -A-.

Fig 3: Removing Heat Exchanger

Courtesy of AUDI OF AMERICA, LLC

-- Loosen both coolant pipes -D- and -E- from the heater core connections -A-.

-- Remove the heater core -A- in the direction of the -arrow-.

NOTE:

This illustration shows a heater core with connectors as it is installed in production (Fig 3). If the heater core was already replaced once, then both coolant pipes are held in the replacement heater core with a bracket -A-. Remove the bolt -B- on this heater core. Install a longer screw -C- (with a M5 thread) all the way to the end as shown in the illustration and with this screw, loosen the bracket -A- from the connection.

Fig 4: Identifying Replacement Heater Core With Bracket

Courtesy of AUDI OF AMERICA, LLC