Emptying tank for reducing agent using SCR vacuum boxVAS 6557 — VW

🧭 Before you start

Fits: platform codes AU1, BX5

• Also covered elsewhere: Service net → Environment → Workshop disposal

🔧 Engine codes this applies to

📋 Procedure

1. ⚠ Danger due to escaping reducing agent.To prevent large amounts of reducing agent from escaping when the metering line is opened, it is necessary to wait until automatic return of the reducing agent is completed . — Open tank flap.
2. Clean area around tank flap.
3. Switch off ignition.
4. Unscrew cap (1) from filler neck for reducing agent.
5. Close shut-off taps (A), (B) and (C).

6. Connect coupling (D) to connection on shut-off tap (A).
7. Pressurise compressed air hose with compressed air.
8. Open shut-off tap (A).
9. Close shut-off valve (A) as soon as the pressure gauge registers a pressure of 0.8 bar.
10. Disconnect coupling (D) from connection on shut-off tap (A).
11. Interrupt the compressed air supply through the compressed air hose.
12. Guide end of hose (E) into the filler neck until it contacts the bottom of the tank for reducing agent.
13. Open shut-off tap (B). [Note: The reducing agent is then drawn from the tank and into the vacuum boxVAS 6557 by the vacuum. The capacity of the vacuum boxVAS 6557 is 11 litres. This extracted volume is sufficient for removal of the reducing agent tank. If the tank for reducing agent holds a greater amount and the tank is to be emptied, then repeat the process.]
14. To empty vacuum boxVAS 6557, hold connection on shut-off tap (C) over suitable container and open shut-off taps (A) and (C).
15. ⚠ Never reuse extracted reducing agent. For information on storage and disposal, see Service net → Environment → Workshop disposal. For country specific information about storage and disposal, ask the importer. — Flush out vacuum boxVAS 6557 thoroughly using water when work sequence is complete.

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