300E 4MATIC (124.230) L6-3.0L (103.985) (1990)
Heater Core And Related Parts
5. Remove the four screws, 2 clips and the heater-A/C box top cover (1).
6. Remove the retaining clamps (2 & 3) on the left and right sides.
7. Disconnect and pull out the three pipes (4) on the heater core.
8. Pull the heater core (5) up and out of the heater-A/C box.
INSTALLATION:
1. Transfer the foam rubber strip (7) from the old heater core to the replacement unit.
2. Using new O-rings (6), install the new heater core in reverse order of removal.
3. Refill the cooling system and check for leaks and proper operation of the heating system.