Inspect cooling system for leaks

AR20.00-P-1010MTA

Inspect cooling system for leaks

09.06.2016

Engine

133 in model 117, 156, 176

1

Cap

3

Tester cap

2

Coolant expansion reservoir

4

Pressure pump

 Danger !

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



Remove

1

Switch on ignition

2

Adjust heater to maximum heat output

3

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

 Unscrew cap (1) slowly and relieve overpressure.

4

Check coolant level and antifreeze content coolant



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.



Drain/fill in coolant

AR20.00-P-1142MTA

5

Screw on tester cap (3) at coolant expansion reservoir (2)

 Test cap

*210589009100

6

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

 Pressure pump

*124589242100

7

Apply test pressure to cooling system

Test pressure for pressure-testing the engine cooling system

*BE20.30-P-1005-01A



Check

8

Perform a visual inspection on the components carrying coolant

 Check condition and coolant loss for all coolant carrying components 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 springs if necessary in order to avoid coolant loss.



Open and close coupling

AR09.41-P-1311-01AL



Install

9

Actuate pressure relief button on the pressure pump (4) and remove test pressure in cooling system

10

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

11

Unscrew tester cap (3) at coolant expansion reservoir (2)

12

Switch off ignition

13

Check coolant level



Notes on coolant level

AH20.00-P-1142-01CW

14

Screw cap (1) onto coolant expansion reservoir (2)

Radiator or expansion reservoir cap

Number

Designation

1-stage cover latch

2-stage cover latch

BE20.30-P-1005-01A

Test pressure for pressure-testing the engine cooling system

Overpressure

bar

1,4

1,4