Inspect cooling system for leaks

AR20.00-P-1010MNG

Inspect cooling system for leaks

12.11.2018

Engine

177 in model 253

Shown on engine 276.8

1

Cap

2

Coolant expansion reservoir

3

Tester cap

4

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

Topical note

Notes on coolant

AH20.00-N-2080-01A

Notes on coolant level

AH20.00-P-1142-01CW



Remove

1

Switch on ignition

2

Adjust heater to maximum heat output

3

Remove front and central sections of the lower engine compartment paneling

AR61.20-P-1105LW

4

Remove cap (1) at coolant expansion reservoir (2)



Check

5

Check coolant level and antifreeze content of coolant; correct if necessary

 Cooling system

*BF20.00-P-1001-02LA

 Coolant mixing ratio

*BF20.00-P-1001-04A

6

Attach tester cap (3) to coolant expansion reservoir (2)

 Test cap

*210589009100

7

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

 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 cooling system

*BE20.30-P-1002-01D

9

Perform visual inspection of the condition of the coolant conducting assembly parts and connections and coolant loss

In the event of pressure loss



Replace damaged assembly part.

10

Drain off overpressure over valve at pressure pump (4)

 Pressure pump

*124589242100

11

Disconnect pressure pump (4) from tester cap (3)

 Pressure pump

*124589242100

12

Remove tester cap (3) on coolant expansion reservoir (2)

 Test cap

*210589009100

13

Check coolant level and antifreeze content of coolant; correct if necessary

 Cooling system

*BF20.00-P-1001-02LA

 Coolant mixing ratio

*BF20.00-P-1001-04A



Install

14

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

15

Install front and central section of the lower engine compartment paneling

AR61.20-P-1105LW

16

Switch off ignition

Cooling system check values

Number

Designation

Engine 177

BE20.30-P-1002-01D

Test pressure for pressure-testing the cooling system

Overpressure

bar

1,4

 Cooling system

Number

Designation

Engine 177 in model 253

BF20.00-P-1001-02LA

Cooling system

Workshop replacement amount

Main circuit

Liter

11,1

Low-temperature circuit

Liter

4,6

Antifreeze/water

Down to -37°C

%

50/50

-38°C and below

%

55/45

Specifications for Operating Fluids, sheet

BB00.40-P-0310-01A

Specifications for Operating Fluids, sheet

BB00.40-P-0325-06A

Specifications for Operating Fluids, sheet

BB00.40-P-0326-06A

 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