Inspect cooling system for leaks

AR20.00-P-1010EZ

Inspect cooling system for leaks

02.12.2019

Engine

780 in model 169.090

Shown on expansion reservoir (1) for the high-temperature cooling circuit

1

Expansion reservoir

2

Tester cap

3

Pressure pump



Check

 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

 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

General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system

AH00.00-Z-0300-01A

Topical note

Notes on coolant

AH20.00-N-2080-01A

1

Open engine hood and secure against falling down

When performing a leak test on the high-temperature cooling circuit or the low-temperature cooling circuit.

2

Rotate cap on expansion reservoir (1) half a revolution counterclockwise, release overpressure, then unscrew the cap

3

Check coolant level; correct if necessary

Notes on coolant level

AH20.00-P-1142-01CW

4

Mount tester cap (2) on expansion reservoir (1)

 Test cap

*169589009100

5

Connect pressure pump (3) at tester cap (2)

 Pressure pump

*124589242100

6

Apply a pressure of max. 0.8 bar to the cooling system


The leak test may only be carried out with an overpressure of max. 1.4 bar.
Otherwise the high-voltage battery will be damaged.

Engine 780 in model 169.090Test pressure for pressure-testing the engine cooling system

*BE20.30-P-1005-01A

7

Check cooling and heating hoses as well as their connections for proper condition and coolant loss, check condition and seating of hose clamps

8

Release pressure in cooling system at pressure pump (3)

9

Remove the pressure pump (3) and tester cap (2)

 Test cap

*169589009100

 Pressure pump

*124589242100

10

Screw cap onto expansion reservoir (1)

11

Close the service cover on the right side

When performing a leak test on the battery cooling circuit.

12.1

Close liftgate

When performing a leak test on the battery cooling circuit.

12.2

Close engine hood

When performing a leak test on the high-temperature cooling circuit or the low-temperature cooling circuit.

Radiator or expansion reservoir cap

Number

Designation

1-stage cover latch

BE20.30-P-1005-01A

Test pressure for pressure-testing the engine cooling system

Overpressure

bar

1,4