Heater Core: Service and Repair
HEAT EXCHANGER, REPLACING
Note! The illustrations in this service information are used for different model years and/or models. Some variation may occur. However, the essential information in the illustrations is always correct.
Preparatory work
Removing components
- Clamp the heat exchanger's radiator hoses in the engine compartment.
- Adjust the steering wheel to its lowest position.
- Remove the upper steering wheel cover, held in place with the 4 outer recessed screws on the underside.
Remove:
- the sound baffle on the driver's side
- any knee bolster. Leave the bracket in place and undo the screws at the floor.
- Remove the sound baffle on the passenger side.
For 760/960 MY 88-94:
- Remove the 8 screws and remove the center console.
For 960 MY 95-97:
- Remove the 4 screws and remove the center console.
For S90/V90 MY 97-98:
- Raise the control panel around the gear selector.
All vehicles:
- Carefully pry loose the control panel from the outside.
- Remove the switches and unplug the connectors.
Caution! These panels are extremely fragile and must be detached and reinstalled with extreme care.
Remove:
- the ashtray
- the 2 screws at the lower mounting behind the location of the ashtray.
Note! If the vehicle does not have a large front radio, remove the partition between the upper and lower radio compartment.
- Remove the radio.
Detaching the right control panel, 760/960 MY 88-94:
Remove:
- the panel at the heat control using a bone knife
- the 2 screws and detach the panel around the radio opening. Press in the clips on the sides and pry out the panel
- the switches and unplug the connectors.
Detaching the right control panel, 960/S90/V90 MY 95-98:
- Detach the panel by inserting a screwdriver and releasing the clip while gently pulling out the panel.
Remove:
- the panel with a rotating movement
- the switches and unplug the connectors.
All vehicles:
Remove:
- the 4 screws and remove the control panel
- the connectors.
760/960 MY 88-94:
- Very carefully remove the decor strips on the right and left side
All vehicles:
Remove:
- the 3 air vents around the combined instrument panel
- the 2 sealing washers above/in front of the combined instrument panel
- the screws of the rim: 9 for 760/960 MY 88-94 and 7 for 960/S90/V90 MY 95-98
- the 4 screws and the connectors of the combined instrument panel.
Remove:
- the fuse box from the bracket and move it aside
- the 5 screws of the bracket.
- Remove the 4 screws of the air vents on the air distribution box for front floor, left and right side
- Remove the 2 screws of the air distributor. Bend down the left air duct to the rear floor and remove the air distributor rearward and to the left.
Remove:
- the air ducts at the air distribution box
- the screw of the air distribution box with the air duct of the centre air vents.
Remove:
- the 2 insulating mats, which are stapled in place
- the 2 screws of the air distributor plus the pipe connections of the outer defroster vents.
Note! Note how the following is done before installation.
- Bend out the air distributor and pry away the driver's side air duct as necessary.
Removal
Removing vacuum hoses and distribution housing
Remove:
- the vacuum hoses of the vacuum motors
Note! Note the position of the vacuum hoses.
- any connector for the temperature sensor in the distribution housing
- the lower and left screws (x7) of the distribution housing.
Removing the distribution housing
- Remove the remaining screws from the distribution housing - 3 on top and 1 on the right side.
Note! The screw on the right is screwed in from the top and must be removed.
- Carefully pry loose the distribution housing.
Removing the heat exchanger
Note! Save the heat exchanger seal.
Remove:
- the 4 screws of the 2 heat exchanger retainers
- the heat exchanger
Installation
Installing the heat exchanger with gasket
Note! If possible, transfer the gasket from the old heat exchanger. Otherwise, place a similar gasket on the same mating faces.
- Install the heat exchanger by threading through the moving parts out to the engine compartment and fasten the mountings, 4 screws. Tighten alternatingly.
Installing the distribution housing and vacuum hoses
Note! Clean the temperature sensor (if fitted) and the inside of the distribution housing.
- Reuse the sealant, but make sure it is evenly distributed on the sealing surfaces.
Note! Make sure that the vacuum hoses are not pinched between the gasket surfaces.
Install:
- the distribution housing, starting with the 3 top screws. Make sure the housing is properly seated in the right mounting, insert the screw and tighten
- tighten the 4 screws on the underside and the 3 screws on the left side. Tighten
- the vacuum hoses as follows:
red mark: upper vent, top
blue mark: defroster vent, all the way back
yellow mark: lower floor vent, all the way down
transparent/beige mark: Bi-level vent in the center
- any connector for the temperature sensor in the distribution housing.
Installing the air distributor for the floor and its vents
- Bend down the left air duct to the rear floor and press in the air distributor from the side/front so that it ends up below the distribution housing.
Install:
- the screw of the air distributor
- the 4 screws of the front floor vents.
Installing the fuse box bracket and fuse box
Note! The ground cable to the front bracket mounting.
Install:
- the 5 screws of the bracket and tighten
- the 4 screws of the front floor vents.
Installing the defroster air distributor, air mixture box and sound baffle
Note! Install the air distributor as noted.
Install:
- the 2 screws of the defroster air distributor, at the same time connecting the air ducts of the outer defroster vents. Tighten.
- the screw of the air mixture box with air duct to the center defroster vents
- the sound baffle with staples or hot glue
- the 2 air ducts to the distribution box.
Installing components
Install:
- the 4 screws to the combined instrument panel
- the screws of the rim around the combined instrument panel: 9 for 760/960 MY 88-94 and 7 for 960/S90/V90 MY 95-98
For 760/960 MY 88-94:
- Very carefully install the decor strips on the right and left side.
All vehicles:
Install:
- the 2 sealing washers above/in front of the combined instrument panel
- the 3 air vents around the combined instrument panel
- the 2 connectors and 4 screws of the heating and ventilation control panel
- the 2 screws of the right control panel with switches
- the radio
- the left control panel with switches
- the sound baffle on the driver's side
- the sound baffle on the passenger side
- the center console.
Finishing
Check
- Check the function and perform self-diagnostics.