Hope will replace the pistons for the new SS versions, only it is as far as im aware needs the piston seals changed also. And keep an eye on them. It’s been seen that the early ones they caught or nicked the seals fitting them, so any leakage, you’ll need to return them
full internal routing though past the motor so it’s right pain to remove the rear brake.
Thats the really really annoying thing about Ebikes and their really really annoying internal hose/cable routing.
.
Still haven’t fitted my new rear T4V4 because theres too much work involved, and i don’t like the idea of removing the motor to get the new hose routed through.
I think the only thing is to surface mount it. Get some little sticky on hose guides, and while Im not happy about it, some zip ties too. Not ideal, but it will save a lot of faffing about.