Audi A8 2003 Workshop Manual page 255

8-cylinder TDI engine (4.2 ltr. 4-valve common rail), mechanics - Edition 12.2013
♦ Adapter for cooling system tester - V.A.G 1274/9-
Test condition
• Engine must be warm.
Procedure
– Remove cover above coolant expansion tank -arrows-.
WARNING
Hot steam or hot coolant can escape when expansion tank is
opened; cover filler cap with cloth and open carefully.
– Open filler cap on coolant expansion tank.
– Attach cooling system tester - V.A.G 1274 B- with adapter -
V.A.G 1274/8- to coolant expansion tank.
– Use hand pump on cooling system tester to create a pressure
of approx. 1.0 bar.
If the pressure drops:
– Trace leak and repair.
Checking pressure relief valve in filler cap
– Attach cooling system tester - V.A.G 1274 B- with adapter -
V.A.G 1274/9- to filler cap.
– Use hand pump on cooling system tester to create pressure. Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
• The pressure relief valve should open at a pressure of
1.4 ... 1.6 bar.
If the pressure relief valve does not open as described:
– Renew filler cap.
1. Removing and installing parts of cooling system
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