Coolant Reservoir: Service and Repair

Retrofitting Overflow Tank

NOTE: The overflow tank can be retrofitted in the front right wheelhouse.

1 Raise hood to vertical position.
2 Drain coolant in radiator.
3 Remove expansion tank.





4 Insert rubber grommet 100 997 0881 in wheelhouse (Fig. 1, arrow).





5 Install new expansion tank. It is sealed at the overflow hose connection in such a way that the coolant can be drawn back again out of the overflow tank.





6 Fit 20 mm long chafing protection 110 694 04 85 onto the bracket of the expansion tank.





7 Take off right front wheel.
8 Unscrew wheelhouse cover and take out (arrows).





9 Check in wheelhouse whether the bracket for attaching the overflow tank 126 50002 49 is fitted (arrow).





10 If the bracket is not fitted, take out windshield washer bottle, place to the side and remove battery.
11 Remove tension spring of hood.
12 Cut out drilling template.





13 Place drilling template below the right hood hinge at the reinforcing plate and push back far enough (arrow) for a resistance to be felt. Mark both holes and drill (5.5 mm dia.).
14 Insert bracket 123 800 00 18 from the outside and attach in engine compartment with A 5.3 washers and M 5 nuts.





15 Insert tension spring of hood.
16 Install battery and insert windshield washer bottle.
17 Attach bracket 126 430 03 10 to overflow tank. Insert M 4 x 16 bolts and A 4.3 washers at overflow tank and attach to bracket with M 4 nuts.
18 Pour in approx. 1/4 litre of coolant into overflow tank.





19 Screw overflow tank onto bracket at wheelhouse with B 4.8 x 13 self.tapping screws (top arrows).
20 Align overflow tank, mark bottom attaching hole and drill (2.5 mm dia.). Screw in B 4.8 x 13 self tapping screw.





21 Fit hose 115 476 04 26 onto overflow tank, run through rubber grommet into engine compartment and fit onto overflow pipe of expansion tank.
22 Install wheelhouse cover.
23 Fit on front wheel.





24 Pour in coolant. Switch on ignition for this step. On vehicles with automatic climate control. press "DEF" push-button and on vehicles with air conditioner lock both temperature selectors of automatic heater control in "max" position. On vehicles with auxiliary heater, additionally fit plastic hose onto bleeder valve and open valve.
25 Warm up engine by blipping throttle until thermostat opens (approx. 85 °C). Screw on new cap when temperature approx. 60 °C. Switch on auxiliary heater, if fitted. Close bleeder valve of auxiliary heater once coolant flows out free of bubbles.
26 Pressure-test cooling system with leak-tightness tester 001 589 48 21 00 and the relevant hose with cap 605 589 00 25 00.

Parts: