Usage:
3406, 3406B, 3408, 3408B Truck Engines
Description of Change: A new water temperature regulator is being used on the above engines. The new regulator opens at 88 °C (190°F) in comparison with the former regulator that opens at 82 °C (180°F). The new higher temperature regulator will help the engine give improved fuel economy.
Adaptable To: The new 4W4842 Water Temperature Regulator is in effect with 3406B Truck Engines (7FB11526 and Up) and 3408B Truck Engines (28V4681 and Up).
The new 4W4842 Water Temperature Regulator can be used to replace 9N3720 Water Temperature Regulator in earlier 3406 (92U), 3406B (7FB) and 3408 (28V) Truck Engines.
It is important that the fan control, shutter control, alarm control and shutdown control have the correct operating temperature to work with the new 4W4842 Water Temperature Regulator. If the 88 °C (190°F) thermostat is used in place of a 82°C (180 °F) thermostat and the fan control is not readjusted, the fan will operate excessively. Excessive fan operation will give reduced fuel economy. When the new regulator is installed, make adjustments or replacements to the controls for the attachments as shown in the charts.
