The system must provide frost resistance:
- frost resistance at temperatures up to -25°C ±2 for countries with cold and moderate climates;
- frost resistance at temperatures down to -40°C ±2 for countries with very cold climates.
Schematic diagram of the cooling system of H4J engines:
1 - engine;
2 — engine cooling system radiator;
3 - expansion tank;
4 - water-oil cooler;
5 - water pump pulley;
6 - thermostat;
7 — thermostat housing;
8 — heater radiator;
9 - turbocharger;
10 - water electric pump;
11 - drain plug;
12 — nipple for bleeding the brake drive.
Place a container under the engine to collect the coolant. Open the drain plug (1) of the cooling system radiator.
Blow compressed air through the expansion tank opening using an air-powered spray gun to remove as much coolant as possible.
Fill the cooling system with water through the expansion tank. Run water through the system until the water coming out of the radiator outlet hose of the cooling system is clear.
Using a compressed air spray gun, force a stream of compressed air through the opening of the expansion tank to flush out as much water as possible.
Close the drain plug of the cooling system radiator.
Filling using the tool (Mot. 1700) Fill the engine cooling system with the fluid recommended by the manufacturer using the tool for filling and bleeding the cooling system (Mot. 1700).
Method of refueling without a special device
Caution: Be sure to remove all drain bolts to remove as much air as possible from the cooling system. Failure to do so may result in the cooling system not being completely filled and may cause engine damage.
Remove:
- air bleed nipple (2) from the thermostat housing;
- bleed nipple (3) for removing air from the heater radiator hose.
Fill the engine cooling system with the liquid recommended by the manufacturer, pouring it into the expansion tank up to the top edge of the neck.
Close all the plugs to remove air as soon as the liquid starts to flow out in a continuous stream.
Pressurize the system using a cooling system tester and the valve in the expansion tank cap. Fill the tank with coolant until it starts to overflow.
Tighten the expansion tank cap.
Clean surfaces that have been exposed to coolant.
Caution: Do not open the air bleed plug while the engine is running to prevent engine failure.
Turn off the air conditioning system to prevent the electric fan from turning on when the operation begins.
Start the engine.
Maintain the engine speed at 2500 rpm using the pedal pressure device until the electric fan operates for the second time. Check the heater for proper operation.
Allow the engine to cool down to a coolant temperature below 50°C.
Bring the coolant level up to the "Max" mark.
Install the expansion tank cap.