Inspect cooling system for leaks

AR20.00-P-1010NKE

Inspect cooling system for leaks

18.11.2019

Engine

780 in model 242

Modification notes

26.09.2014

Mixing ratio for coolant

BF20.00-P-1001-04A

1

Low-temperature circuit cap

2

Coolant expansion reservoir

3

Cooling circuit cap

4

Tester cap

5

Pressure pump

 Warning

Risk of injury due to fan starting unexpectedly

Do not reach into the rotation or hazard area of the fan. Wear closed and close-fitting work clothes.

AS20.40-Z-0001-01A

 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

 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

Topical note

Information on preventing damage to electronic components due to electrostatic discharge

AH54.00-P-0001-01A

Topical note

Notes on coolant

AH20.00-N-2080-01A



Remove

1

Unscrew low-temperature circuit cap (1) on coolant expansion reservoir (2)

For working on low-temperature circuit.

 Open low-temperature circuit cap (1) slowly and relieve overpressure, then unscrew low-temperature circuit cap (1).

2

Unscrew cooling circuit cap (3) on coolant expansion reservoir (2)

For working on cooling circuit.

 Open cooling circuit cap (3) slowly and relieve overpressure, then unscrew cooling circuit cap (3).

3

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

Notes on coolant level

AH20.00-P-1142-01CW

 If antifreeze content of coolant is too low, either antifreeze protection must be added or the coolant must be replaced.

 Coolant mixing ratio

*BF20.00-P-1001-04A

4

Screw tester cap (4) onto coolant expansion reservoir (2)

For working on low-temperature circuit.

 Test cap

*210589009100

5

Screw tester cap (4) onto coolant expansion reservoir (2)

For working on cooling circuit.

 Test cap

*169589009100

6

Connect pressure pump (5) to tester cap (4)

 Pressure pump

*124589242100

7

Apply a test pressure of a maximum of 1.4 bar to the cooling system


The test pressure must not be greater than 1.4 bar.
Damage can occur to the cooling system otherwise.



Check

8

Perform a visual inspection on the assembly parts carrying coolant

 Check condition and coolant loss for all coolant carrying assembly parts 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 water heat exchanger into the oil circuits.

 Check condition and seating of the Henn coupling. Replace safety spring if necessary to avoid coolant loss.



Install

9

Remove test pressure in the cooling system

 To do this actuate pressure relief button on the pressure pump (4).

10

Detach pressure pump (5) from tester cap (4)

11

Unscrew tester cap (4) at coolant expansion reservoir (2)

12

Check coolant level

Notes on coolant level

AH20.00-P-1142-01CW

13

Unscrew low-temperature circuit cap (2) on coolant expansion reservoir (1)

For working on low-temperature circuit.

14

Screw cooling circuit cap (3) onto coolant expansion reservoir (2)

For working on cooling circuit.

 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