Service consists of totally dismantling the watch and movement, stripping the movement down to component parts and examining the wearing parts for any signs of damage or wear. For 218 series, extra attention is paid to the center wheel post and center wheel, which are prone to corrosion and seizure. All parts are then ultrasonically cleaned, and the movement reassembled. In the mean time, the case is dismantled and cleaned, as well the bracelet also. If required by the owner, the crystal is replaced, or at least it is buffed to removed scratches.
During reassembly, several different lubricants are used in the movement as follows (and of course depending on the watch type):After reassembly, the movement is powered up and phased to obtain best setup of the index system. After running for 4 hours, the movement is then placed on a Vibrograf M80 timing machine (or M90 for some electronic watches, or B200 for some mechanical watches) and then the rate adjusted.
The movement is then cased up and set aside to run for several days. This is due to the fact that the tuning fork will change its rate slightly when removed from the watch, and it takes a day or two for it to settle back into a steady and consistent rate again. The rate is again checked and adjusted to the final value. At reassembly a new case gasket is fitted, and if a 214, a new battery hatch gasket and if needed a crown O ring. Also, the crystal is buffed to remove light scratching. Finally, the crown is lubricated with "seiko" silicon grease on reassembly.
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