Remove/install air recirculation unit in rear

AR83.60-S-7175E

Remove/install air recirculation unit in rear

24.04.2020

Model

447.7/8

with code H13 (Additional heat exchanger)

Model

447.7/8

with code HZ7 (TEMPMATIC semi-automatic air conditioning in rear)

Model

448

Modification notes

31.03.2020

Work procedure updated.

The whole document

Shown on model 447.8 with code HZ7 (Semi-automatically controlled air conditioning, TEMPMATIC in rear passenger compartment)

1

Electrical connector

4

Air duct

6

Screw

2

Drain hose

5

Coolant hoses

7

Air recirculation unit

3

Air duct

 Warning

Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.

Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers.
Wear protective gloves, protective clothing and safety glasses.

AS20.00-Z-0001-01A

Topical note

Information on preventing damage to electronic components due to electrostatic discharge

AH54.00-P-0001-01A

Topical note

General information on vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system as well as personal protective equipment

Typ 447.8 mit Motor 780.702

AH00.00-Z-0300-01A

Topical note

Protect air conditioning circuit and components from moisture when carrying out repair work

AH83.30-N-0005-01A

Topical note

Notes on carrying out repair work in the vehicle interior

AH68.00-N-0001-01S

 

Remove/install

1

Remove cap at coolant expansion reservoir.

 Model 447.7 with engine 622, model 447.7/8 with engine 274, 651, 654, model 448
Initially, unscrew cap at coolant expansion reservoir of engine cooling system counterclockwise as far as the safety catch and relieve overpressure. Then unscrew the cap.

 Model 447.8 with engine 780.702
Initially, unscrew cap at coolant expansion reservoir of auxiliary circuit counterclockwise as far as the safety catch and relieve overpressure. Then unscrew the cap.

2

Remove left side wall refrigerant lines.

Model 447.7/8
with code HZ7 (TEMPMATIC semi-automatic air conditioning in rear)
Model 448

AR83.50-S-6501E

 Installation: Only install rear quarter in rear passenger compartment after the leak check of the coolant circuit.

3

Disconnect electrical connector (1).

4

Remove drain hose (2) from air recirculation unit (7).

Model 447.7/8
with code HZ7 (TEMPMATIC semi-automatic air conditioning in rear)
Model 448

5

Remove air duct (3) from air recirculation unit (7).

Model 447.7/8
with code HZ7 (TEMPMATIC semi-automatic air conditioning in rear)
Model 448

6

Remove air duct (4) from air recirculation unit (7).

7

Clamp off coolant hoses (5).

 Clamp

*000589543700

8

Remove coolant hoses (5) from air recirculation unit (7).

 To do so, release clamps at coolant hoses (5).

 Collect escaping coolant using suitable vessel.

 Hose clamp pliers

*454589003700

9

Remove screw/bolts (6).

10

Remove air recirculation unit (7).

11

Remove rear air conditioning system refrigerant shutoff valve at air recirculation unit (7).

When replacing air recirculation unit (7).

Model 447.7/8
with code HZ7 (TEMPMATIC semi-automatic air conditioning in rear)
Model 448

AR83.50-S-9000E

12

Install in the reverse order.

13

Correct coolant fluid level and carry out leak check of coolant circuit in area of air recirculation unit (7).

Model 447.7 with engine 622, model 447.7/8 with engine 274, 651, model 448 with engine 274

AR20.00-S-1010E

Model 447.7/8 with engine 654

AR20.00-S-1011E

* Applies to Europe only



Drain/fill coolant of auxiliary circuit
Model 447.8 with engine 780.702

AR08.50-S-0022G

 Before the leak check, the auxiliary circuit must be bled using the diagnostic system.