Removing and installing heating-system heat exchanger — AUDI

Special tools, testers and auxiliary items required

Hose clamps 3093 or 3094
Collector V.A.G 1306

Removing right heat exchanger

Note:

Pay attention to sequence on RHD vehicles: Remove left heat exchanger first.

Switch off ignition.
Removing windscreen wipers and cowl panel trim:

=> Electrical system; Repair Group 92; Servicing windscreen wipers
Electrical system
Servicing windscreen wipers

=> Electrical system; Repair Group 92; Servicing windscreen washer system
Electrical system
Servicing windscreen washer system

Open cap on coolant expansion tank.
Place collector V.A.G 1306 below engine.
Drain coolant circuit:

=> Engine Mechanical Components; Repair Group 19
Engine Mechanical Components

Mark positions of coolant hoses -A- and -B-.
Detach coolant hoses -A- and -B- from engine to pump valve unit.

Note:

Fig shows arrangement in 8-cylinder engine.

Hold coolant hose -A- over a vessel.
Use compressed-air gun to carefully blow coolant out of pump valve unit and heat exchangers by way of coolant hose -B-.
Detach connectors to pump valve unit.
Removing reinforcement plate (plenum chamber) =>Page
80-21
.

Note:

To ensure that coolant is blown out of both heat exchangers, alternately pinch off upper coolant hose to one of the two heat exchangers.

Slacken off bolt -A- for coolant pipe holder (in plenum chamber) approx 2 turns.
Removing glove box and side trim of centre console:

Remove footwell vent.

Cover carpet in area beneath heat exchanger with impermeable sheeting and absorbent paper.
Remove clamps -A- and -B-.
Push both coolant pipes towards "plenum chamber".
Screw out bolts -C-.
Remove bracket.
Pull out heat exchanger.

Installing

Installation is carried out in the reverse order to removal, noting the following:

Secure all hose connections with hose clamps of latest design:

=> Parts list

Always replace gaskets and seals -D-.
Checking cooling system for leaks before installing side trim

=> Engine Mechanical Components; Repair Group 19
Engine Mechanical Components

Notes:

Coolant circuit must be bled before starting up coolant circulation pump -V50 of pump valve unit.
Dry running of the pump valve unit will destroy it.

Bleed coolant circuit before attaching two-way connector to pump valve unit

=> Engine Mechanical Components; Repair Group 19
Engine Mechanical Components

Before installing heat exchanger, check openings -A- of condensate drain for dirt and clean if necessary.

Notes:

Condensate drain valve must not be gummed up with wax or underseal; it must close properly.
Fig. shows drain openings with heat exchangers in position.

Cleaning:

Heat exchangers removed: Reach through opening in heat exchangers and clean condensate drains using for example, a piece of wire.
Heat exchangers fitted: Clean condensate drains from outside using, for example, a piece of wire.

Removing left heat exchanger

Removing windscreen wipers and cowl panel trim:

=> Electrical system; Repair Group 92; Servicing windscreen wipers
Electrical system
Servicing windscreen wipers

=> Electrical system; Repair Group 92; Servicing windscreen washer system
Electrical system
Servicing windscreen washer system

Removing right heat exchanger => Page
80-48
.

Note:

Pay attention to sequence on RHD vehicles: Remove left heat exchanger first and also E-box/plenum chamber connection point.

Removing driver's shelf and side trim of centre console:

Slacken off bolts -A- and -B- of clamp-type clips for coolant pipes approx. 2 turns.
Remove footwell vent.

Cover carpet in area beneath heat exchanger with impermeable sheeting and absorbent paper.

Remove clips -A- and -B-.
Push both coolant pipes towards "plenum chamber".
Pull out heat exchanger towards passengers' side.

Installing

Installation is carried out in the reverse order, when doing this note the following:

Further installation operations => Page
80-51
.