Abstract: A leakage detection apparatus for drum wheels having a pair of plates which sealingly engage the wheel to define an inner first chamber under vacuum, a reciprocating container enveloping the engaged plates and wheel to define an annular helium chamber sharing the wheel as a common wall with the inner first chamber, a probe gas introduced into the annular helium chamber, and a mass spectrometer, in gaseous communication with said inner first chamber scanning for a trace of the probe gas indicating the presence of a leak path in the structual integrity of the wheel. A method of use is also disclosed.