I opened the radiator cap, and the radiator is dry; there is no coolant at all.

But the reservior indicates it is in medium level of coolant?

Does that mean I need a water pump?

Thanks a lot.

 

Make sure the hose from the radiator to the reservior is connected and has no leakes. Make sure it reaches into the bottom of the reservior and it's able to flow coolant. If all of that checks out OK, put a new rad. cap on and add coolant to the system.