SEAT Workshop Service and Repair Manuals

Removing and installing heat exchanger Special tools and workshop equipment required

t  Cooling (leak) tester -SAT 1274- (and adaptors)

t  Clamping tool -U-30042- t  Compressed-air gun, commercially available t  Hose clamps up to 40 mmorhose clamps up to 25 mmPliers -T20174- Removal: –  Place protective covers over driver's and front passenger's seats. –  Switch ignition OFF. –  Release the pressure in coolant circuit by opening cap on the coolant expansion tank → Engine, mechanics; Rep. gr.19. –  Remove the components that prevent access to the coolant hoses to the heat exchangers in the engine compartment -A- and -B- → Engine - Mechanics; Rep. gr.13

–  Mark positions of coolant hoses -A- and -B-.   Note t  Depending on the engine and the vehicle version, it may be necessary to release or remove the following components (upper cover of the engine, air conduit to the throttle and the intake manifold etc.) → Engine /Mechanics; Rep. gr.13

t  There are different versions of the heat shield -B-. In version „1“ the nuts need not be removed for panel -A- nor the heat shield removed -B- from the vehicle (coolant hoses can be disconnected with the panel in place).

t  In version „2“ it is necessary to remove the disks -A- and the clips-C- and release the vehicle heat shield -B-. t  For clarity, the illustration shows the heat shield -B- with the engine removed –  Release the heat shield -B- from the front wall of the windscreen wiper tray (if fitted and when necessary) and place it to one side (or remove completely).

–  Pull back the heat shield hoses -D- and -E- (if fitted) so that fitting can be performed, for example, of the clamps up to 40 mmpliers -T20174--F- on the coolant hoses-A- and -B-.

–  Mark positions of coolant hoses -A- and -B-.   Note t  The heat exchanger has been designed for the certain flow direction of the refrigerant; for this purpose, the hoses must be connected to the correct side (Hose -A-: Supply from cylinder head, Hose -B-: Return tube to the water pump). t  The position of the refrigerant hoses is the same for vehicles with heating or air conditioning. This illustration shows the position in a vehicle with air conditioner. t  Bleed the coolant circuit of air → Engine, mechanics; Rep. gr.13. –  Disconnect the air release tube (from the upper junction -A- to the coolant expansion tank). –  Cover the area below the tube joints -A- and -B- (e.g with absorbent paper). –  Pinch off both coolant tubes leading to the air conditioner (heating) system heat exchanger (e.g. using the hose clamps up to ø 40 mmpliers -T20174-) and detach them.

–  Attach a tube section -A- to each top connection. –  Keep a suitable recipient -B- under the lower connection -C-. –  Use compressed-air gun to carefully blow coolant out of heat exchanger (into container -B-).

–  Remove bolt -A- from connecting flange -B- (so that coolant pipes can be moved for removal of heat exchanger). –  Remove the driver side lower lining → Bodywork, interior fitting work; Rep. gr.68. –  Remove the vent from the foot well area on the left side → Chapter. –  For those vehicles with an additional electric heating, remove the Additional heating element -Z35- (with Additional air heating control unit -J604-) → Anchor.

–  Remove 4 bolts -A- and detach cover -B-.   Note t  This diagram shows the air conditioning version with additional electric heating

t  There are different versions of the cover -B- (for vehicles with or without additional electric heating). t  If lever -C- is located in such a position to the left of the temperature flap, that prevents access to the upper screw -A-, the ignition must be switched on and another temperature setting must be selected on the Heating control unit -J65-, Air conditioning control unit -J301-, Climatronic control unit -J255- for the left side. –  Cover the floor in the area under the heat exchanger with an impermeable layer and absorbent paper.

–  Remove bolts -A- and detach clamps -B- from connections of coolant pipes -C- and -D- at heat exchanger -E-. –  Release the coolant tubes -C- and -D- from the heat exchanger -E- (move the coolant tubes to the transverse panel). –  Pull heat exchanger -E- out of air conditioning unit (heater). Installation Attach in reverse order; note the following:

–  Check seals -A- and -B- attached to heat exchanger. Only fit a heat exchanger with undamaged seals.   Note t  The seal may curl up when it is inserted if it has not been bonded on properly. t  Cold air may flow past the heat exchanger if the seal is damaged or not properly fitted.

t  From model year 2005 onwards, additional foam strips -A- are bonded to corners of heat exchanger -B-. These foam strips -A- should prevent certain knocking noises that may especially occur in vehicles with diesel engines. Apply these strips with all heat exchangers (e.g. self-adhesive foam with the spare part number 191 819 069 → Spare parts catalogue)

–  With heat exchanger removed, check air conditioning unit (heater) for contamination (via slot -A- for heat exchanger). –  Remove any dirt or remnants of escaped coolant from air conditioner (heating) unit (e.g. after removing leaking heat exchanger). –  Fit heat exchanger into the air conditioning (heater).

–  Remove old clamps -B- from both coolant pipes -C-. –  Attach new clips -A- (included with delivery of new heat exchanger) to both heat exchanger coolant pipes as shown. –  Lightly humidify the new seals -A- (included with delivery of new heat exchanger) using coolant. –  Insert new seals -A- in the connections of the heat exchanger -D-. –  Press both coolant pipes -C- into the connections of the heat exchanger -D-. –  Re-check the position of the seals -A- between the coolant pipes -C- and the connections of the heat exchanger -D-.

–  Attach the two coolant pipes -C- and -D- with clips -C- to heat exchanger. –  Tighten bolts at clamps -A- to 2.5 Nm.

–  Check position of both clamps -B- after tightening bolts -A-; they must surround flange completely at heat exchanger and coolant pipe and not make contact with other components.

–  Insert bolt -A- in connecting flange -B- (when doing so, make sure bolt is screwed in at intended attachment point).

–  Check the correct positioning of the grommet -B- in the transverse panel. –  Seal the flanges for the coolant hoses to the heat exchanger -A- in the openings of the grommet -B-, for example using silicon sealing paste (so that it is water tight).

–  Make sure coolant hoses are properly connected to heat exchanger. Observe markings: A -  Supply from cylinder head B -  Return tube to the water pump –  Re-install components removed in reverse order with the exception of the heat exchanger connection cover and the driver side lower covering. –  Bleed the coolant circuit of air → Engine, mechanics; Rep. gr.19.   Note t  The seal of the coolant circuit can be checked in the following manner, for example: t  Bleed coolant circuit. t  Carefully open cap on coolant expansion tank (observe safety precautions for opening cap) → Engine, mechanics; Rep. gr.19. t  Increase the pressure in the coolant circuit, for example using the cooling (leak) tester -SAT 1274- (and the adaptors). t  When bleeding the coolant circuit, take particular care to ensure that the heat exchangers are bled completely. If there are still air bubbles in the heat exchanger, the client may complain of low heating power in the winter or a different vent air temperatures for the same setting on the control → engine, mechanics; Rep. gr.19.

–  Check coolant circuit for leaks, paying particular attention to connection between coolant pipes and heat exchanger, → Engine, mechanics; Rep. gr.19. –  Re-install the heat exchanger connection cover and the driver side lower covering and all other removed components.