Inspect cooling system for leaks

AR20.00-P-1010MFG

Inspect cooling system for leaks

14.02.2020

Engine

139 in model 118, 177, 247

Modification notes

27.01.2020

Cooling system

BF20.00-P-1001-06J

1

Coolant expansion reservoir

2

Tester cap

3

Pressure pump

 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

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

Topical note

Notes on coolant

AH20.00-N-2080-01A

Notes on coolant level

AH20.00-P-1142-01CW



Remove

1

Remove upper engine cover.

If leaks occur in engine cooling system.



AP01.10-P-2405-01K

2

Remove bottom engine compartment paneling.

If leaks occur in engine cooling system.

AR61.20-P-1105MFA

3

Remove cap from coolant expansion reservoir (1).



Check

4

Check antifreeze content of coolant.

 Cooling system

*BF20.00-P-1001-06J

If antifreeze content is too low,



Replace coolant.

AR09.41-P-6834MFG

5

Check coolant level.



AP20.30-P-2050T

6

Attach tester cap (2) to coolant expansion reservoir (1).

 Test cap

*210589009100

7

Connect pressure pump (3) to tester cap (2).

 Pressure pump

*124589242100

8

Apply a test pressure to the engine cooling system for 2 minutes.


Do not exceed the specified test pressure.
Damage will occur otherwise to the engine cooling system.

 There should be no pressure loss within a period of 2 minutes.

Test pressure for pressure-testing the engine cooling system

*BE20.30-P-1005-01A

9

Check condition of all coolant carrying component parts and connections and check for leak tightness.

 There is the possibility that the coolant can find its way over a defective cylinder head gasket into the combustion chamber or over a defective heat exchanger into the oil circuit.

If coolant loss is detected:



check coolant-carrying components for inner leaktightness, replace if necessary.



Install

10

Reduce test pressure in coolant circuit via pressure release button on pressure pump (3).

 Pressure pump

*124589242100

11

Remove the pressure pump (3) from the tester cap (2).

 Pressure pump

*124589242100

12

Remove tester cap (2) on coolant expansion reservoir (1).

 Test cap

*210589009100

13

Check coolant level.



AP20.30-P-2050T

 Cooling system

*BF20.00-P-1001-06J

14

Attach cap to coolant expansion reservoir (1).

15

Install lower engine compartment lining.

If leaks were present in engine cooling system.

AR61.20-P-1105MFA

16

Install upper engine cover.

If leaks were present in engine cooling system.



AP01.10-P-2405-01K

Radiator or expansion reservoir cap

Number

Designation

2-stage latch cover

BE20.30-P-1005-01A

Test pressure for pressure-testing the engine cooling system

Overpressure

bar

1,4

 Cooling system

Number

Designation

Engine 139 in model 118, 177, 247

BF20.00-P-1001-06J

Cooling system

Workshop replacement amount

Main circuit

Liter

11,6

Low-temperature circuit

Liter

2,6

Antifreeze/water

to -37 °C

%

50/50

as from -38 °C

%

55/45

References to sheet specification

BB00.40-P-0310ZZ