Master Cylinder bleed nipple weaping

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SteveE

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Hi, I have just replaced the factory master cylinder on my 2015 S1000rr with a brembo RCS. The problem is the bleed nipple on the master cylinder won?t stop weaping.
any ideas ? Do I just need to replace the nipple ?
thanks in advance,
 
Re: Master Cylinder balled nipple weaping

from the thread or out the top? if thread you could use some ptfe tape,but be as easy to get a new nipple.if it's new it shouldn't be doing it so send it back
 
Re: Master Cylinder balled nipple weaping

It’s weaping from the thread, I would have thought if it was letting by then it would leak from the top and thread.
 
Shouldn't leak at all, the threads don't do the sealing the cone shape at the bottom does. I would try a new nipple.

Have you tightened the nipple enough or to much?
 
Hi, both my and my mate's RCS did that.... We tried different bleed nipples in case the angle of the machining on the 'seat' is wrong. Brembo Reseller just said they can take a surprising amount of force, so we did them up at double the recommended torque setting and all was fine. Even ptfe didn't do it.
 
not sure i'd be keen on tightening something into a cast bit of metal at twice the stated torque,it it leaks it's not right (especially if new) and needs sending back or fixing properly.i know it's only a bleed nipple,but brakes are parts you dont **** about with imo.
 
Hi, I totally understand your point of view. I would certainly swap it out.

It's just it's not uncommon and our replacements did the same. The std torque setting is 7.5 Nm which is tiny for an M10 1.0 i.e fine pitch. Even 15Nm is tiny. Try 15Nm on a normal M8 or M10 bolt to get the feel of how low it is. I would bet alot of owners go over 7.5Nm whilst bleeding their brakes using a spanner. I've never seen a professional mechanic even at world championship level use a torque wrench on detail stuff like bleed nipples.

P.S My background includes building TT bikes for Hizzy, Foggy etc including winners and mechanicing for HRC. British Championship. Jamie
 
not sure those credentials are good enough ;)

tbh i've never torqued them,just "tightened" them but then again i've never had any issues regarding leaking (i have had brake fail at aragon though,which was interesting) might torque it next time to get a feel for what i actually do compared to reccomened.no doubt i'm well over 7.5!!
 
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