Here is my Seiko Bullhead. The name is derived from the crown and chronograph pushers being at the 12 position so it then looks like bull horns. In reality is is more to do with ease of use for timing. You can hold it more like a stopwatch should you want to time something.
Like anyone into mechanical watches I have a fascination with chronograph movements as they appear so complex. The irony of all this is for me at least I hardly ever use the for timing anything, I just like to play with them!
So like all of my watches this one comes with a story. I had been after this model for a long time but they seem to be quite pricy and I always like a bargain and it has to be a project too. One day my good friend Kwan who I have bought parts from and in return serviced some of his watches offered me a this watch for a price I could not say no to. He said it runs but has problems, a sub hand is missing, pushers and crown are aftermarket but I know you like a project. Needless to say I snapped his hand off for this one.
The model did not come on a bracelet but luckily there are aftermarket ones available on eBay that I bought.
For this model I decided that I would document this one on film as it would make some good content plus as its a movement I had not worked on before I would surely be in for a a bit of fun on film.
Part one was filmed in November 2021 which in many ways was a disgrace for me as I actually bought it in September 2020!
Here is part one:
The disassembly was easy enough but then the watch got pushed to one side for many months until I found the time to get round to it. The parts were very dirty and it took many rounds in the ultrasonic and the cleaning machine to get somewhere near decent.
I then inspected the parts and found that the hour recording wheel pinion was bent.
Many in my Facebook group suggested I could bend this one back into position but I was not so sure and decided to buy a replacement instead. This took another month of searching and nothing came up, Kwan asked me how I was getting on, I explained and two days later he sent me a replacement part!
I then decided to rebuild the movement off camera first to get some practice. I figure as some people like to follow along with my videos that I should at least look like I know what I am doing if I am to help others… I was able to build the train up and as they are similar to a Seiko 6139 I only build the train and do not put the chronograph works on. This means I can test the movements performance and if there was a problem its easier to diagnose and sort. Of course there was a problem! the third wheel. On running the movement the top pivot broke off. I was confident that these movements shared common parts across the 6### series and that a 3rd wheel from a 6119 would be compatible. Fortunately I have many 6119 parts so quickly set about fitting the replacement wheel.
On testing the same thing happened! the pivot broke and this time stayed in the jewel. I wracked my brain over this. Why was the pivot breaking? Annoyed I put it all back in the box and on the shelf for a rainy day.
Months went by and I started to think about it again and if that 3rd wheel was right or not. It wasn’t. I pulled the part sheets that are available on my site in the resources tab and checked the part numbers. From memory I think the 3rd wheel works on the 6139 but not the 6138!
Weeks go by and I am at a local watch fair with some friends and was discussing this with them. Simon Wilkinson, a guy who is a Seiko wizard and now repairs and services vintage Seiko for a living said he had a spare wheel that I could have. How lucky was I! 6138 parts are hard to find.
So the part turned up and this time the camera came out for the rebuild:
Here is the Bullhead in all its glory two years in the making! okay I replaced the bezel as I wanted a cleaner look. I also need to paint and lume the hands as they are a bit of a mess really. All in good time though!
Here is the finished watch. A Seiko icon for any vintage Seiko collector.
BULLFIGHT
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