A dairy farmer had complaints about uneasiness of the cows during milking. The problems started after changing some parts of the milking machine. Therefore a dynamic milking machine test was carried out to detect the cause of the problems. This test showed that the drainage ability of the milking machine was insufficient in cows with a high milkability (> 4.0 kg/min). The cyclic variations in the short milk tube and the drop of the mean vacuum in the short milk tube did not comply with the standards in cows with a high milkability. Moreover, in these cows, the mean vacuum in the beginning of the long milk tube was too low. Beside, the vacuum in the mouthpiece of the teat cup liner in cows with small teats was far above the standards and the shut off valves in the claws, which must lock the exit to the long milk tube nipple when the cluster is taken off automatically, did not function anymore. The way these deviations disturbed the milking procedure, is discussed. The farmer was advised (i) to replace the automatic cluster remover system by an electronically controlled one. (ii) and to replace the milking claws by claws with a larger volume (iii) and to replace the teat cup liners by teat cup liners with a smaller diameter. After the implementations of all advises, the cows were at ease again.