Inspect cooling system for leaks

AR20.00-P-1010W

Inspect cooling system for leaks

12.11.2018

Engine

152, 276 in model 172

Shown on model 172 with engine 276.9

1

Cap

2

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

Notes on coolant level

AH20.00-P-1142-01CW



Remove

1

Switch on ignition

2

Adjust heater to maximum heat output

3

Remove lower engine compartment paneling

AR61.20-P-1105W

4

Unscrew cap (1) on expansion reservoir (2) slowly

5

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

 Engine 152 in model 172Cooling system

*BF20.00-P-1001-06C

 Engine 276.8 in model 172
Engine 276.9 in model 172Cooling system

*BF20.00-P-1001-02BA

6

Mount tester cap (3) onto 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 can occur on the engine cooling system otherwise.

 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



Check

9

Check all coolant carrying assembly parts and connection for coolant loss

In the event of pressure loss.

There is no visible coolant loss recognizable.



Check coolant carrying assembly parts for inner leaktightness.



Install

10

Drain off overpressure over valve at pressure pump (4)

11

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

12

Detach tester cap (3) on expansion reservoir (2)

13

Switch off ignition

14

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

 Engine 152 in model 172Cooling system

*BF20.00-P-1001-06C

 Engine 276.8 in model 172
Engine 276.9 in model 172Cooling system

*BF20.00-P-1001-02BA

15

Screw cap (1) onto expansion reservoir (2)

16

Install lower engine compartment paneling

AR61.20-P-1105W

Radiator or expansion reservoir cap

Number

Designation

1-stage cover latch

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

1,4

 Cooling system

Number

Designation

Engine 276.8 in model 172

Engine 276.9 in model 172

BF20.00-P-1001-02BA

Cooling system

Workshop replacement amount

Main circuit

l

10,4

10,4

Low-temperature circuit

l

3,4

-

Antifreeze/water

Up to -37°C

%

50/50

50/50

As of -38 °C

%

55/45

55/45

Specifications for Operating Fluids, sheet

BB00.40-P-0310-01A

BB00.40-P-0310-01A

Specifications for Operating Fluids, sheet

BB00.40-P-0325-06A

BB00.40-P-0325-00A

Specifications for Operating Fluids, sheet

BB00.40-P-0326-06A

BB00.40-P-0326-00A

 Cooling system

Number

Designation

Engine 152 in model 172

BF20.00-P-1001-06C

Cooling system

Workshop replacement amount

Liter

9,5

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-0325-00A

Specifications for Operating Fluids, sheet

BB00.40-P-0326-00A