Heating and A/C Unit Heat Exchangers, Removing and Installing

Heating And A/C Unit Heat Exchangers, Removing And Installing

Special tools, testers and other items required
- Hose clamps 3093/3094
- Commercially available compressed-air gun
- Cooling system tester V.A.G 1274 (and appropriate adapters)

Heat exchanger, preparation for removal
- Switch off ignition.
- Dissipate pressure in coolant circuit by opening cap at coolant expansion tank.
- Remove left and right plenum chamber covers.
- Detach Engine Control Module (ECM) and lid of electronics box.
- Unplug 2-pin connector from Coolant Pump - V50- of pump/valve unit.







- Mark positions of coolant hoses -A- (supply to pump/valve unit) and -B- (return to engine).
- Pinch off both coolant hoses from engine to pump/valve unit (using hose clamp V.A.G 3094 for example).
- Detach coolant hoses -A- and -B- from connections.







- Attach hose sections -A- and -B- to the two connections.
- Place collector -C- beneath hose -B-.







- Use hose clamp, for example, to pinch off return from heat exchanger on front passenger's side -D-.
- Use compressed-air gun to carefully blow coolant out of heat exchanger on driver's side and pump/valve unit (into collector).
- Detach hose clamp from hose -D-.
- Use hose clamp, for example, to pinch off return from heat exchanger on driver's side -B-.
- Use compressed-air gun to carefully blow coolant out of heat exchanger on front passenger's side and pump/valve unit (into collector).
- Detach hose clamp from hose -B-.







- Slacken off bolt -A- securing coolant pipe holder (in plenum chamber) by approx. 2 turns.
- Remove coolant pipe holder -B-.
- Moisten contact surface between both coolant pipes -D- and -E- at grommet -C- slightly with silicone lubricant (to ensure that pipes can be moved without changing position of grommet).