Another tool arrives on the doorstep! It's a nice face spanner tool with swappable metric sized pinions. I think it is used for vehicles, but I got it for the piston disassembly and will also be useful on my Boema. It is much bigger than I thought, that square hole is for a 1/2" drive if you need more leverage and the base tool is already a foot long!

I heated up the piston and struck it on the face with a mallet before I placed the upper group in the vise by the bearing bolts. The hole size is 5mm on the piston face, and with a nice firm tug the tool worked perfectly and the piston began unscrewing. The mountains of grease likely keep the threads of the rod and piston in pristine condition, and when I started unscrewing the piston a strong smell reminding me of an oily smell seen on museum ships entered my sinuses. I placed a few zip ties but it was not needed as the thread is longer than the fully relaxed spring.


With the piston and spring off I could take off the bearing bolts with a 17mm deep socket wrench. This allows the lever fork to be maneuvered up and out of the upper group casting with the two-piece rod. The rod pin has a knurled end, so I did a light tap on the opposite side to release the fork from the rod assembly.


I heated up the piston and struck it on the face with a mallet before I placed the upper group in the vise by the bearing bolts. The hole size is 5mm on the piston face, and with a nice firm tug the tool worked perfectly and the piston began unscrewing. The mountains of grease likely keep the threads of the rod and piston in pristine condition, and when I started unscrewing the piston a strong smell reminding me of an oily smell seen on museum ships entered my sinuses. I placed a few zip ties but it was not needed as the thread is longer than the fully relaxed spring.


With the piston and spring off I could take off the bearing bolts with a 17mm deep socket wrench. This allows the lever fork to be maneuvered up and out of the upper group casting with the two-piece rod. The rod pin has a knurled end, so I did a light tap on the opposite side to release the fork from the rod assembly.










































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