I always do a thermostat with any cooling system repair for insurance. Also this system can be hard to purge of air. Just spend time and pour in the coolant (Factory coolant only!!) very slowly! Just give it time and turn on the heat on high.
All new clamps are ideal as well.
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM