The B737 main gears have shimmy dampers joining the two halves of the torque links. This allows the gears to castor a little. It is very noticeable when trying to back an aircraft into a hangar docking with the hyds unpressurised, when it keeps going sideways and you have to tow it out and start again.
The shimmy dampers are pressurised with u/c down hyd fluid, but there is no return line, so they will leak when they relieve.