The 1915 Çanakkale Bridge is a recently completed suspension bridge, characterised by a main span of 2023m which is the world's record. The bridge restraint system is quite complex in order to guarantee safety under traffic, wind and seismic actions. It comprises 8 fluid viscous dampers, 4 large bearings designed to withstand compression load as well as tension load and horizontal displacement, 8 lateral elastomeric bearings for transversal restraint and 8 hydraulic end-stop devices. This paper focuses on the eight special fluid viscous dampers that provide large energy dissipation capacity to the bridge under earthquake. They are characterized by a load capacity of 5000 kN, a stroke of ±1.25 m and a maximum design velocity of 1 m/s. The paper describes the dynamic and static tests carried out on two full scale viscous dampers according to the test protocol that includes the European Standard EN 15129:2009 type tests and additional contract specifications.