Howdy Folks,
I installed a aux. tank in the trunk of my 83' 300d with 3/8 coolant hose attached to a heat exchanger in the tank. I also have the Frybrid heated filter that uses 5/8 coolant hose. I have both the 3/8 and the 5/8 lines in one sequence with an adaptor near the filter for the differing hose sizes. I have the lines hooked at the heater core inlet and at the water pump.

However, I cant get the coolat to flow through the system properly. I tried burping it with the lower radiator hose. Any thoughts? Thanks in advance.
Cheers!
Lukas