Check coolant auxiliary circuit for leaktightness

AR08.50-D-0014TE

Check coolant auxiliary circuit for leaktightness

26.11.2019

Engine

780.703 in model 910

1

Expansion reservoir

3

Tester cap

2

Cap

4

Pressure pump

 Danger

Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)

Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.

AS00.00-Z-0035-01A

 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

General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system

AH00.00-Z-0300-01A

Topical note

Notes on coolant

AH20.00-N-2080-01A

Notes on coolant level

AH20.00-P-1142-01CW



Check

1

Remove cap (2) of expansion reservoir (1).

 Turn cap (2) counterclockwise only up to the safety catch and relieve overpressure. Then unscrew cap (2).

2

Check coolant level in the expansion reservoir (1).

If the coolant level is not correct,



Correct coolant level.



Anticorrosion agent/antifreeze (specification 325.5)

BB00.40-P-0325-05A

3

Attach tester cap (3) to the expansion reservoir (1).

 Test cap

*210589009100

4

Attach pressure pump (4) to the tester cap (3).

 Pressure pump

*124589242100

 Test cap

*210589009100

5

Apply test pressure to the auxiliary circuit.


Do not exceed the specified test pressure.
Otherwise, damage may occur on the auxiliary circuit.

Test pressure for auxiliary circuit

*BE08.50-N-1002-01TE

6

Check auxiliary circuit for leak tightness.

 Perform a visual inspection of the engine compartment from above.

If coolant loss has occurred,



Localize and eliminate cause.

7

Remove lower engine compartment lining

AR61.20-D-1105TS

8

Remove underbody paneling.

AR61.30-D-1001TS

9

Remove underfloor paneling from the high-voltage battery carrier.

AR61.30-D-1002TE

10

Check auxiliary circuit for leak tightness.

 Perform visual check of the engine compartment and high-voltage battery from below.

If coolant loss has occurred,



Localize and eliminate cause.

11

Install underfloor paneling on the high-voltage battery carrier.

AR61.30-D-1002TE

12

Install underbody paneling.

AR61.30-D-1001TS

13

Install lower engine compartment lining.

AR61.20-D-1105TS

14

Actuate pressure release button on the pressure pump (4) and relieve test pressure in the auxiliary circuit.

 Pressure pump

*124589242100

15

Remove pressure pump (4) from tester cap (3).

 Pressure pump

*124589242100

16

Remove tester cap (3) from the expansion reservoir (1).

 Test cap

*210589009100

17

Check coolant level in the expansion reservoir (1).

If the coolant level is not correct,



Correct coolant level.



Anticorrosion agent/antifreeze (specification 325.5)

BB00.40-P-0325-05A

18

Attach the cap (2) of the expansion reservoir (1).

Cooling system

Number

Designation

Engine 780.703 in model 910

BE08.50-N-1002-01TE

Test pressure for auxiliary circuit

bar

1,4