The invention relates to a method for detecting leakage of a hollow component, comprising the steps of sealing said hollow component (1, 31), creating a pressure difference P1 and P2 between said hollow component interior and an adjacent compartment/enclosure (2, 32), putting a tracer gas in one of the hollow component or said compartment/enclosure, waiting for an enriching time T and then carrying out a step of transferring, via a non-selective or selective restriction (6, 7; 49), the content of said hollow component or said compartment/enclosure (2; 32) into which tracer gas has not been put, in order to concentrate, in a volume downstream of said restriction (6, 7; 49), the tracer gas that said content may possibly contain, and then in looking for the presence of tracer gas in said volume. The invention also relates to an installation for implementing the method.