Cooling system — coolant hose connection diagram (Audi A4 B8)

Caution! Risk of burns from hot steam and hot coolant. When the engine is warm, the cooling system is under excess pressure. To relieve excess pressure, place the expansion cap over the expansion tank. coolant reservoir with a rag and carefully open it. To secure all hose connections, use clamps of the appropriate series. Arrows applied to the ends of the tubes and hoses of the system. cooling, must be located opposite each other.

Hose connection diagram

Blue = large coolant circuit. Red = small coolant circuit. Orange = cooling circuit for the cylinder block. Brown = heating circuit. The arrows show the direction of coolant flow.

Cars without independent heater

Car with independent heater

Draining and filling the coolant

Remove noise insulation shields "1" and "2". Place a VAS 6208 oil pan under the engine. Unscrew the "arrow" plug of the connecting pipe and drain the coolant.



Remove the coolant hose from the left front pipe by loosening the hose clamp "arrow" and drain the coolant.

Bay

The ignition is off.

Note: The cooling system is filled with a coolant solution and coolant additives for the entire year. Only coolant specified in the Electronic Parts Catalog should be used. Other concentrates may worsen the properties of the coolant, especially its anti-corrosion properties. The resulting damage may cause leaks in the system. cooling and lead to serious engine malfunctions. A coolant with the correct ratio of mixture components prevents the formation of corrosion and limescale. In addition, they increase the boiling point. For this reason, the cooling system, regardless of the time of year, must be filled with a coolant based on a concentrate with anti-corrosion additives. Especially in countries with tropical climates and high engine loads, coolants with a high boiling point reliably protect the engine during operation. The freezing point of the coolant must be at least -25°C (in countries with an arctic climate, at least -35°C). It is also prohibited to reduce the proportion of concentrate in the coolant during the warm season or when operating in countries with a warm climate by adding it to the system. cooling water. The concentrate content should be at least 40%. If climatic conditions require a lower freezing point for the coolant, the concentrate content can be increased, but not more than 60% (the freezing point will then be approximately -40°C). Exceeding this limit will increase the freezing point again, and the coolant's heat capacity will also decrease. Use only clean drinking water when mixing coolants. Reusing drained coolant is permitted only if the radiator, heater heat exchanger, cylinder head, cylinder head gasket or cylinder block have not been replaced. To check the concentrate in the system. a refractometer should be used for cooling. To secure all hose connections, use clamps of the appropriate series.

Ratio of components in coolant

• Additive (40%) and water (60%) to ensure freezing temperature of -25°C.
• Additive (50%) and water (50%) to ensure freezing temperature of -35°C.

Close the drain plug "arrow". Connect the coolant hose with the clamp "arrow" to the left front coolant pipe. Fill the system filling device reservoir with coolant. cooling at least 12 liters of pre-mixed coolant in the correct proportion: Screw on the system tester adapter. cooling "VAG 1274/8" to the expansion tank. Install the device for filling the system. cooling on the adapter "VAG 1274/8". Place outlet hose "1" into a small container "2". The exhaust air will capture a small amount of coolant, which must be collected. Close taps "A" and "B" by turning them perpendicular to the direction of flow. Connect hose "3" to the compressed air line. Pressure: 6...10 bar excess pressure.



Open valve "B" by turning it in the direction of flow. A vacuum is created in the cooling system using an ejector pump; the indicator arrow should be in the green field. Open tap "A" briefly, turning it parallel to the direction of flow so that the hose of the tank of the device for filling the system. the "VAS 6096" cooling system is full of coolant. Close valve "A" again. Open valve "B" for 2 minutes. A vacuum continues to be created in the cooling system using the ejector pump; the indicator arrow should be in the green field. Close valve "B". The indicator arrow should remain in the green field, in which case there is a vacuum in the system. cooling will be enough for its subsequent filling. If the arrow is below the green field, then you should repeat the previous operations. When the vacuum decreases, check the system. cooling for leaks. Remove the compressed air hose. Open tap "A".





Remove the system filling device. cooling with adapter "VAG 1274/8" on expansion. tank. Attach the tube "VAG1274/10" on the adapter "VAG 1274/8". Fill with coolant until the system tester tube reaches the level. the cooling system was completely filled. If necessary, add more during the air removal process.



Remove the "arrow" engine cover. Remove the seal from the front wall of the water drain box. Remove the cover of the water drainage box.



Open the bleed screw "arrow" of the coolant tube while the coolant is draining. Close the bleed nipple.





Loosen and remove the system hose. cooling, going to the heat exchanger, so that the coolant comes out of the vent hole "arrow" in the system hose. cooling. Place the coolant hose onto the connecting fitting and secure it with a clamp. On a vehicle with independent heating, turn on the heater for approx. for 30 seconds.



Tighten the expansion cap until it clicks. coolant reservoir. Start the engine.

Duration	Engine speed	Condition
3 minutes	2000 rpm	Air conditioner "Off", LED in the AC button is not lit. Heater "HI", fan speed as low as possible (= 0)
Both large coolant hoses on the radiator are warm	Idling	Air conditioner "Off." Heater "HI."
2 minutes	2000 rpm	Air conditioner "Off." Heater "HI."

Turn off and let the engine cool. Install noise insulation screens. Check the coolant level. When the engine is cold, the coolant level should be at the -MAX- mark. If the engine is warmed up to operating temperature, the coolant level may be above the -MAX- mark.

[The original version of the article is posted on the website AUDIMANUAL]