Check coolant thermostat

AR20.10-G-2455DD

Check coolant thermostat

21.08.2019

Engine

900.91/92 in model 000.001

Engine

902.91/93 in model 000.001

Engine

904.94/95/96/97 in model 000.001

Engine

906.90/93/94/95/96/98/99 in model 000.001

Engine

924.91/93/94 in model 000.001

Engine

925.9 in model 000.001

Engine

926.91/92/93/95/97/98 in model 000.001

Coolant thermostat (1) with short valve (1/2)

1

Coolant thermostat

1/1

Main valve

1/2

Bypass valve

Coolant thermostat (1) without short valve

1

Coolant thermostat

1/1

Main valve

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A



Check

1

Remove coolant thermostat (1).

AR20.10-G-2460DD

2

Suspend coolant thermostat (1) on a wire in a container filled with water.

3

Heat water with a suitable heat source and constantly measure water temperature with temperature measuring instrument.


On no account use a welding torch or soldering torch to heat the coolant thermostat (1).
The coolant thermostat (1) will be damaged otherwise.

 Stir water so that temperature of water is the same at all points.
The heating speed should, from approx. 8 °C below start of opening of main valve (1/1), not be more than 1 °C/min to 2 °C/min.

Coolant thermostat start of opening

*BE20.10-N-1001-02I

4

Continue to heat the water until the bypass valve (1/2) is closed.

For coolant thermostat (1) with short valve (1/2).

 When closing bypass valve (1/2) compare indicated actual value on temperature measuring instrument with the specified value.

Coolant thermostat bypass valve closed at

*BE20.10-N-1003-02I

If specified value is not achieved,



Replace coolant thermostat (1).

5

Determine start of opening of main valve (1/1).

 When opening the main valve (1/1) compared the displayed actual value on the temperature measuring instrument with the specified value.

Coolant thermostat main valve

*BE20.10-N-1002-02I

If specified value is not achieved,



replace coolant thermostat (1).

6

Continue to heat the water until the main valve (1/1) is fully opened.

 For a fully opened main valve (1/1) compare indicated actual value on temperature measuring instrument with the specified value.

Coolant thermostat main valve

*BE20.10-N-1002-02I

If specified value is not achieved,



replace coolant thermostat (1).

7

Remove coolant thermostat (1) from container and measure distance between collar at coolant thermostat (1) and disk of main valve (1/1).

 Measurement must take place immediately after removing the coolant thermostat (1) from the vessel.

8

Note down measured value.

9

Allow coolant thermostat (1) to cool down until main valve (1/1) is closed.

10

Measure distance between the collar on the coolant thermostat (1) and the plate of the main valve (1/1).

 With the aid of this measurement value and the previously noted measurement value, calculate the actual value for the stroke of the main valve (1/1).

Coolant thermostat main valve

*BE20.10-N-1002-02I

If specified value is not achieved,



replace coolant thermostat (1).

11

Install coolant thermostat (1).

AR20.10-G-2460DD

Check values for coolant thermostat

Number

Designation

Engine 900.9, 902.9, 904.9, 906.9

Engine 924.9, 925.9, 926.9 in model 000.001

BE20.10-N-1001-02I

Coolant thermostat start of opening

°C

83 (2)

83 (2)

Check values for coolant thermostat

Number

Designation

Engine 900.9, 902.9, 904.9, 906.9

Engine 924.9, 925.9, 926.9 in model 000.001

BE20.10-N-1002-02I

Coolant thermostat main valve

Full opening

°C

95

95

Stroke

mm

8

8

Check values for coolant thermostat

Number

Designation

Engine 900.9, 902.9, 904.9, 906.9

Engine 924.9, 925.9, 926.9 in model 000.001

BE20.10-N-1003-02I

Coolant thermostat bypass valve closed at

°C

92

92