Pressure Build Up!!!

[Tom Power]

I filled it with 100ml. put it all back together, new thermostat and rad cap, flushed the coolent and brought her for a quick spin to heat it up so i can burb it, but the fan still spins by hand when she was hot. I can hear it roaring though. I only drove about 2 miles to get the heat up and coolant circulating.

[Brussels john]

Maybe this will explain what a viscous Fan/Coupling unit does.
Just a note. YOU SHULD ONLY PUT 50ML Of Silicon oil in a Surfs Viscous fan.
If it is reasembled correctly it will work perfectly.

A viscous coupling is made up of alternating circular plates. The plates have tabs or perforations in them. The plates are mounted in a sealed drum, and are located very close to each other. The drum is filled with silicone, or some dilatant fluid. When the two sets of plates are rotating in unison, the fluid stays cool and remains in a liquid state. When the plates start rotating at two different speeds, the shear effect of the tabs or perforations on the fluid will cause it to heat up and solidify (Silicone when heated will turn into a near solid; the viscosity of dilatant fluids rapidly increases with shear). The fluid in this state will essentially glue the plates together and transmit power from one set of plates to the other. The size of the tabs or perforations on the plates, along with the number of plates and fluid used will determine the strength and onset of when this mechanical transfer will happen.

Hope this helps

[Tom Power]

Fitted back the fan with the new silocone oil, fitted new thermostat and rad cap, flushed the coolant system. Every thing is running sweet now... Cheers for the help...