W116

On the 80 300sd that I just purchased it had a shutoff valve between the engine block and the tube coming from the auxillary water pump. I have replaced the thermostat and coolant but I was not getting any increase in temp on the hose leading to the aux. pump. I know this has something to do with the climate control so I wanted to see if there was a blockage or if the valve was frozen shut. I used a thermo gun to see the different temps. When I reconnect3ed the hose without the valve there4 was no coolant flowing out so I assume this is where I mite have had a air pocket.

Is it worthwile to attach the clear bowl to the bottom of the Fuel manager? I am figuring that by remounting the Manager on the flat plate a little higher I mite be able to mount the clear bowl on the bottom of the Fuel manager.