Safety rules when working with the power supply system (VW Polo 4)

The fuel system is under pressure! Before releasing the hose connections, the fuel pressure must be relieved. To do this, briefly remove and then screw the fuel filler cap back on. Cover the connection with a thick, clean cloth. Put on safety glasses and only then, carefully releasing the connection, relieve the fuel pressure.

Caution: On the AXU petrol engine with direct injection, this method can only relieve pressure in the low-pressure circuit (up to 5 bar). To relieve pressure in the high-pressure circuit (up to 100 bar) special equipment required.

The high-pressure circuit includes the fuel lines from the high-pressure pump fixed at the rear of the cylinder head to the injectors. In a diesel engine with a working volume of 1.9 liters, the temperature of the high-pressure fuel lines, and in a diesel engine equipped with pump injectors, the fuel temperature can reach +100°C in extreme cases. Before releasing the fuel lines, it is necessary to allow the fuel to cool down, since there is a serious risk of scalding.

• No open flames, no smoking, no hot or very hot parts near the work area. Risk of accident! Have a fire extinguisher ready.
• Be sure to provide good ventilation in the workplace. Fuel vapors are toxic.
• Put on protective gloves.
• Work with protective glasses.