A method is presented for reducing time loss during manufacture and testing of a hard disk drive by predicting reduction in gas fill. The method includes using servo tracking error to obtain a measured value of insitu non-repeatable runout (NRRO) for the hard disk drive, the hard disk drive having been filled with the gas and semi-sealed. The measured value of NRRO is then deconvolved into a plurality of values for flow induced NRRO components. These values of NRRO and of flow induced NRRO components are compared to predetermined limiting values and a time when one of the predetermined limiting values will be reached is predicted. Action is then applied as appropriate.