Inspect cooling system for leaks

AR20.00-S-1010E

Inspect cooling system for leaks

25.05.2020

Model

447 with engine 274, 622, 651

Model

448 with engine 274

Modification notes

20.05.2020

Work procedure revised

The whole document

 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

Remove lower engine compartment lining

AR61.20-S-1105E



Check

2

Set heater control to max. output.

3

Switch auxiliary heating to max. output.

Model 447 with code H12 (Auxiliary water heater) Model 447 with code H13 (Additional heat exchanger at the rear) Model 448

4

Open coolant expansion reservoir.

 Turn cap on coolant expansion reservoir counterclockwise through half a revolution, release overpressure, and then remove cap.

5

Check coolant level.



Engine cooling system - inspecting fluid level, adjusting to correct level

AP20.00-S-2011E



Service Information: Coolant

Model 447 with engine 274, 622, 651

SI20.00-S-0001B

If coolant level incorrect



Correct coolant level.

6

Install tester cap on coolant expansion reservoir.

 Test cap

*210589009100

7

Install pressure pump on tester cap.

 Pressure pump

*124589242100

 Test cap

*210589009100

8

Apply test pressure to engine cooling system.

Test pressure

*BE20.30-N-1004-01B

9

Check coolant hoses and their connections for damage and coolant loss.

In case of damage or coolant loss:



Perform suitable repair measures.

 After obtaining special order.

10

Actuate pressure relief button on pressure pump and reduce test pressure in engine cooling system.

 Pressure pump

*124589242100

11

Remove pressure pump from tester cap.

 Pressure pump

*124589242100

 Test cap

*210589009100

12

Unscrew tester cap.

 Test cap

*210589009100

13

Screw cap onto coolant expansion reservoir.



Install

14

Install lower engine compartment lining.

AR61.20-S-1105E

Check values for engine cooling system cap

Number

Designation

Engine 274 in model 448
Engine 274, 622, 651 in model 447

BE20.30-N-1004-01B

Test pressure

bar

1,5