Servicing a Seiko Kakume 6138-0030 chronograph including example of an un-level hairspring

I just completed servicing this very nice for a ClockSavant customer. Like so many of these vintage Seiko’s, it required a reasonable amount of work to restore to factory or better performance but, in the end, the result is a watch any vintage collector would be thrilled to own. As shown in the pictures, the hairspring was bent and un-level (slanted upwards as shown by the red line) during a previous repair. I manipulated the hairspring back to a correct state, see my other posts to learn more about hairspring manipulation. I wanted to note that generally speaking, anything other than the most basic hairspring manipulation is typically an added cost to servicing. After installation of new lubricated seals, basic corrosion removal, and case cleaning, the watch successfully passed water resistance testing for splashing and rain (3 bar.) After servicing, the watch is now highly accurate as measured in a controlled test, to within 9 seconds a day of variance across all 6 measured positions with an average rate of about +5 second per day. On-wrist performance can vary considerably from that number, you will not typically experience this level of accuracy on-wrist, with the chronograph running, and in-consideration of other factors. The watch also has a very low beat error, and excellent amplitude for a caliber 6138 which can have characteristically lower amplitude.

Seiko Kakume 6138-0030 chronograph servicing

Seiko Kakume 6138-0030 chronograph servicing - bent hairspring

Seiko Kakume 6138-0030 chronograph servicing

Seiko Kakume 6138-0030 chronograph servicing

Seiko Kakume 6138-0030 chronograph servicing

Seiko Kakume 6138-0030 chronograph servicing

Seiko Kakume 6138-0030 chronograph servicing