Inspect cooling system for leaks

AR20.00-P-1010GW

Inspect cooling system for leaks

05.12.2018

Engine

157 in model 463

1

Cap (main circuit)

3

Tester cap

5

Cap (low-temperature circuit)

2

Expansion reservoir (main circuit)

4

Pressure pump

6

Expansion reservoir (low-temperature circuit)



Remove

 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

Notes on coolant

AH20.00-N-2080-01A

1

Switch on ignition

2

Open hood

Opening engine hood, moving to upright position and closing
As of model year 2013 up to model year 2019

AR88.40-P-1000GG

Perform operation step 3 to 14 during leak test of the main circuit

3

Adjust heater to maximum heat output

4

Unscrew cap (1) slowly at expansion reservoir (2) and relieve overpressure



Check

5

Check coolant level and antifreeze content coolant

 Correct if necessary.

 Coolant mixing ratio

*BF20.00-P-1001-04A

6

Screw on tester cap (3) at the expansion reservoir (2)

 Test cap

*210589009100

7

Connect pressure pump (4) at tester cap (3)

 Pressure pump

*124589242100

8

Apply test pressure to cooling system


The specified test pressure must not be exceeded.
Otherwise, damage to the cooling system will occur.

Test pressure for pressure-testing the engine cooling system

*BE20.30-P-1005-01A



Check

9

Perform visual inspection on coolant carrying components

Open and close coupling

AR09.41-P-1311-01AL

 Check condition and coolant loss for all coolant carrying components and connections. The coolant carrying components should be checked for inner leaktightness if there is no external coolant loss. There is the possibility, for example, that coolant can find its way over a defective cylinder head gasket into the combustion chamber or over a defective oil-water heat exchanger into the oil circuits.

 Check condition and seating of the Henn coupling; replace catch springs if necessary.



Install

10

Remove overpressure over the valve at the pressure pump (4) and remove pressure pump (4)

 Pressure pump

*124589242100

11

Unscrew test cap (3) at the expansion reservoir (2)

 Test cap

*210589009100

12

Switch off ignition

13

Check coolant level and antifreeze content coolant

Notes on coolant level

AH20.00-P-1142-01CW

 Coolant mixing ratio

*BF20.00-P-1001-04A

14

Screw cap (1) onto expansion reservoir (2)

Perform operation step 15 to 26 during the leak test of the low-temperature circuit

15

Remove center section of engine cover

 Installation: Ensure correct seating of the engine cover.

16

Unscrew cap (5) slowly at expansion reservoir (6) and relieve overpressure



Check

17

Check coolant level and antifreeze content coolant

 Correct if necessary.

 Coolant mixing ratio

*BF20.00-P-1001-04A

18

Screw tester cap (3) onto the expansion reservoir (6)

 Test cap

*210589009100

19

Connect pressure pump (4) at tester cap (3)

 Pressure pump

*124589242100

20

Apply test pressure to cooling system


The specified test pressure must not be exceeded.
Otherwise, damage to the cooling system will occur.

Test pressure for pressure-testing the engine cooling system

*BE20.30-P-1005-01A

21

Perform visual inspection on coolant carrying components

 Check condition and coolant loss for all coolant carrying components and connections.



Install

22

Remove overpressure over the valve at the pressure pump (4) and remove pressure pump (4)

 Pressure pump

*124589242100

23

Unscrew tester cap (3) from the expansion reservoir (6)

 Test cap

*210589009100

24

Switch off ignition

25

Check coolant level and antifreeze content coolant

Notes on coolant level

AH20.00-P-1142-01CW

 Coolant mixing ratio

*BF20.00-P-1001-04A

26

Screw cap (5) onto expansion reservoir (6)

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

27

Perform an engine test run and check engine for leaktightness

Radiator or expansion reservoir cap

Number

Designation

Engine 100, 102, 103, 104, 110, 111, 112, 113, 114, 115, 116, 117, 119, 120, 121, 123, 127, 129, 130, 133, 137, 139, 152, 155, 156, 157, 159, 166, 180, 256, 260, 264, 266, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 282, 285
2-stage latch cover
Engine 601, 602, 603, 604, 605, 606, 607, 608, 611, 612, 613, 615, 616, 617, 621, 626, 628, 629, 640, 642, 646, 648, 651, 654, 656, 668
2-stage latch cover

BE20.30-P-1005-01A

Test pressure for pressure-testing the engine cooling system

Overpressure

bar

1,4

 Coolant mixing ratio

Number

Designation

Engine all (4xWD, CAR, smart)

BF20.00-P-1001-04A

Coolant mixing ratio

Antifreeze/water

Up to -37°C

%

50/50

As of -38 °C

%

55/45

Overview and specifications sheet

BB00.40-P-0310-01A

References to sheet specification

BB00.40-P-0310ZZ