Iron abundances, surface gravities, effective temperatures and masses of 14 red giants and 16 stars of the giant branch clump in three old open clusters have been determined from DDO photometry. The masses derived for stars in the post-helium-flash stages of evolution, are systematically lower than those found for the pre-helium-flash red giants, the average difference in log(m/mₚ) being -0.44. A second result is that the masses of the clump stars are smaller than the corresponding turnoff point masses. A similar trend between the giants and horizontal branch stars in five globular clusters as well as in the evolved stars of M67 and NGC 7789 has been found from existing DDO photometry. These results are interpreted as demonstrating that the post-helium-flash stars undergo mass loss before reaching their helium core burning phase of evolution. We identify the highest luminosity phase of red giant as that during which mass is lost most rapidly.