A leak detection method for detecting a leak past a dynamic seal in aircraft landing gear (100) comprising: a strut (10); a rod (20) slidably mounted in the strut; and a bearing (70) fitted to an end (11) of the strut to guide the rod (20). The bearing includes a bushing (50) having a seal (62) arranged to rub against the rod (20) to provide sealing between the strut and the rod, defines a fluid chamber (2), and a stop nut (40) for preventing the bushing from moving relative to the strut. The method includes a step of installing a test nut (3) without a wiper seal in the place of the stop nut (40), the step of putting the hydraulic fluid in the landing gear under pressure, and the step of verifying the existence of a leak of hydraulic fluid on the outside surface (22) of the rod (20).