Heater Core: Service and Repair

Heater Core, Removing And Installing

- Remove plenum chamber cover.
- Disconnect battery cables and remove battery.


NOTE:
- Obtain radio code before disconnecting battery.
- On vehicles with power seats, move the seats back as far as possible before disconnecting the battery.


- For vehicles build up to October 1998.
- Remove complete windshield wipers.
- Remove grommet (in pass through hole in plenum chamber).







- Loosen screw -A- and screw out 10 mm, or remove.
- Vehicles build from October 1998 through December 1998:







- Check whether grommet -A- is present in pass- through hose in plenum.
- If grommet -A- is present, completely remove windshield wiper.
- If grommet -A- is not present, remove instrument panel shell.


NOTE:
- Up to October 1998, the central tube for the instrument panel is fastened to the body with a bolt. To remove the bolt, the windshield wiper must be removed.
- Starting October 1998, there was a running change in the fastening method for the central tube. Fastening is now carried out with a bracket and a screw under the instrument panel outer shell on the windshield cross member (to remove, the outer instrument panel shell has to be removed).


- Vehicles starting January 1999:


NOTE:
- From June 1999 different mounting brackets for the brake and clutch pedal were installed (as a running change, first on vehicles with accelerator pedal sensor), on vehicles with these mounting brackets the instrument panel cross member does not have to be loosened anymore to remove the heater core.


Removing heater core
- Release pressure in coolant system by opening cap on coolant expansion tank.







- Clamp off and disconnect both coolant hoses leading to heater core in air conditioner unit (e.g. using VAG 3094)


NOTE:
- The coolant hoses must be re-installed in the correct positions:
-- Coolant hose -A- supply from cylinder head.
-- Coolant hose -B- return to water pump.
- Bleed cooling circuit







- Place container under connection -A- and carefully blow out coolant from heater core (using compressed air) via connection -B-.
- Remove grommet -C-.
- Remove storage compartment on driver's side.







- Unscrew bolt -A- and remove bracket -B.
- Loosen clamp -C-.
- Pull heater core -D- out of air conditioner unit slightly.
- Pull two coolant lines -E- out of heater core.
- Remove heater core


NOTE:
- If heater core cannot be pulled out of air conditioning unit (touching mounting bracket of brake pedal and clutch pedal), loosen instrument panel cross member.
- Always replace clamps -C- and O-rings -F-.
- Install clamps -C- as shown in the illustration, making sure that they are not in contact with air conditioner unit.
- Before installing the storage compartment on the driver's side, check the cooling system for leaks.
- Before installing the storage compartment on the driver's side, make sure that the Wide Open Throttle (WOT) stop of the accelerator pedal is installed in the correct position.
- Bracket -B- is only available on version "1", from version "2" the cover supports the cooling pipes.
- Loosen instrument panel cross member from vehicle.

- Instrument panel cross member should only be loosened on vehicles when heater core cannot be pulled out of air conditioning unit (touching mounting bracket for brake and clutch pedal).


- Removing instrument panel outer shell (not necessary on all vehicles, see notes).







- Remove bolt -A-.
- Removing instrument panel center part (not necessary on all vehicles, see notes).







- Loosen right instrument panel cross member (remove two bolts -2-).







- Remove bolts -A- and detach left instrument panel brace from body.
- Remove screws -B- and remove cover -C-.







- Remove bolt -1- and detach pedal bracket from instrument panel cross member.
- Push adjustable steering column in as far as will go.
- Remove left instrument panel cover.







- Unscrew nuts -2- far enough to allow left side of instrument panel module to be pulled back about 10 mm (0.394 in.)
- Loosen left instrument panel cross member of body.
- Pull back left side of instrument panel module for enough to allow heater core to be taken out of air conditioner unit (past pedal bracket), and secure heater core in position to prevent it from sliding back.

Installing heater core

Installation of the heater core is the reverse of removal.
- Before installing the storage compartment on the driver's side, check the cooling system for leaks (fill coolant circuit, bleed and pressure test).