Bonzo
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- Joined
- May 8, 2022
- Messages
- 847
Bonz, it is possible that when those seals were fitted that the grooves were not properly cleaned out. They can get hard calcium like deposits in them which need scraping out meticulously, otherwise the new seals stand proud and can cause the pistons not to retract properly.
It could be mate, though on a quick glance, the grooves look pretty clean, but I'll have a deep dive over the weekend, prior to (hopefully) refitting and bleeding.
I was just reading the workshop manual actually as the AN tech database differs in it's approach to inserting the outer piston & seal. The manual says, outer seal in first, followed by the piston. AN says...
'The front seal will be butchered by the sharp open lip of the caliper piston. Hence always put the pistons into the seals with the closed end first, which means the outer piston must be put into the body first, then the seal, and then be levered into the seal from the middle of the caliper.'
Regarding the seals standing proud, the Norton workshop manual says..
'It will be noted that the diameter of the seal is larger than that of the seal groove, in order to provide an interference fit. In addition, the seal groove and seal are different in section so that when bedded, the seal feels proud to the touch at the edge furthest from the bore. This is normal.'