Cooling System Drain and Refill

Self-made tool for vehicles with automatic climate control





a = Fixing groove

Coupling (1), part No.002 545 49 28
approx. 1 m cable 1.5 mm square black (b) +
approx. 1 m cable 1.5 mm square brown (c) -
1 cable terminal +
1 cable terminal -






NOTE: A thermostat housing with automatic vent is installed on model 123.1 starting February 1979 (2nd version).

When filling up on vehicles with automatic climate control, proceed as described in Section "B" below.



Draining





Model 115.1






Model 123.1

1 Open radiator cap in steps (only below 90 °C).
2 Unscrew drain plug on radiator.






3 Unscrew drain plug on cylinder crankcase.



Filling-in





Model 115.1

a) Vehicles without automatic climate control

4 Fill-in coolant up to mark on radiator filler neck.
5 On models 115.1 and 123.1 (1st version), open vent screw on coolant thermostat housing until coolant flows out






Model 123.1

6 Start engine and run warm. Mount radiator cap.


b) Vehicles with automatic climate control





4 Slowly fill-in coolant up to mark on radiator filler neck. Do not mount radiator cap.
5 Start engine and run warm up to approx. 40 °C.
6 Pull-off plug of heating water pump (arrow) on feed line. Connect heating water pump to battery with self-made tool and push ,,DEF"-button.
7 Run engine warm under intermittent acceleration until thermostat opens.

NOTE: Mount radiator cap starting at 60 °C.

8 Connect heating water pump again to feed line.
9 Check coolant level (below 90 °C) and fill-up to specified level.