Cooling System - Coolant Reservoir Appears To Be Leaking
19 Coolant reservoir appears to be leaking19 10 07
2009959/5
June 18, 2010
Supersedes Technical Service Bulletin Group 19 number 08-18 dated November 21, 2008 for reasons listed below.
Affected Vehicles
Condition
The coolant reservoir is diagnosed to be leaking and intended to be replaced.
Technical Background
May be caused by the coolant hose -1- between coolant reservoir and radiator or the coolant hose -2- between coolant reservoir and engine which may have internal cracks.
Internal cracks can cause coolant to get inside the coolant hose material and leak from connections to the coolant reservoir (arrows) due to the capillary effect.
Production Solution
N/A
Service
Tool Requirements:
^ VAG1274 Cooling system tester
^ VAG1274/8 Adapter
^ VAG1274/9 Adapter
Before replacing coolant reservoir:
^ Check if coolant hose -1- between coolant reservoir and radiator is leaking at connection to coolant reservoir.
^ Replace that coolant hose if necessary.
^ Run engine or drive vehicle until coolant reaches a temperature of 80°C (176°F).
Coolant reservoir, checking for Leaks:
^ Remove filler cap on expansion tank.
^ Install tester VAG 1274 and adapter VAG 1274/8 on expansion tank (see illustration).
^ Build up a pressure of approximately 1.0 bar with hand pump on tester.
If this pressure is not maintained:
^ Trace and repair leaks.
^ Check if any coolant leak around coolant reservoir still exists.
Pressure relief valve in filler cap, checking:
^ Screw filler cap onto tester with adapter VAG 1274/9.
^ Install hand pump and build up pressure.
^ Pressure relief valve should open at 1.4 to 1.6 bar.
^ Replace filler cap if necessary.
DO NOT replace coolant reservoir if there is no further coolant leak around the coolant reservoir detected.
Warranty
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.