Topic: NEW yamaha maxim brake rebuild... still need help

[the technological J]

i already screwed this up once but i dont know for sure what caused it........ but i bought a new kit and am trying this again my question is what directions are the seals to go in.... obviously they fit in one place... but (im gonna call it the hollow side... up side in the pic) what direction should the hollow side of the seals go? both toward the spring or what( the  right side of the piston)
thanks

[Grnrngr]

in that pic, it looks like maybe yes, but the more correct answer is the "grooved" side holds the fluid, the groove traps the fluid and with pressure applied, expands putting more sealing pressure against the inside of the m/c wall, if it was in backwards, the rounded face would provide little resistance to pressure applied against the fluid, the fluid would squirt right out. they both face the same way, so you want the brake fluid on the grooved side and the brake lever on the other.

[the technological J]

Word... thanks nerdygirlystranger

[Gordon]

nerdygirlystranger

 

[the technological J]

so i put it together and tried to to get pressure with no luck... tried to fill the system best i could with no luck.... i put an old master cylider just to take her for a ride(you know how that is) and had them bled in 3 minutes... the main reason i dont keep that one on is cause it doesnt have the brake switch for the lights in em.... is there something im not doing right with the rebuild? or  can the whole master cylinders go bad?

[Grnrngr]

Hmmm...just looked over my manual for the XV...same master cylinder..it does say inspect master cylinder body for scratches, replace if it's scratched. Kinda thought they mean the inside bore, but I suppose it could be the outside of the plunger they're talking about. Are the passages thoroughly clean and can pass fluid? Also kinda hard to tell from the book diagram, but it looks like the fat end of the plunger goes in first (left side of your pic). Book also says "Note that the cylinder cups are installed with the larger diameter (lips) inserted first", which would mean when inserted, you should see the rounded "face" and not the "groove". Got an extra one in storge somewhere, I'll find it and pull it apart if that would help...