XTR V-Brake bearing lubrication



Y

yoramf

Guest
Hi,

I read that XTR V-brakes (M960) has "self lubricating bearings". Does
it mean that these bearing need no maintenance (cleaning/ lubricating)?

What puzzles me, is that after a ride in muddy conditions, I noticed
that one of the brake arms was seized. It looked as if the bearings of
that arm were seized. After playing with the arm, it got loose, but now
the movements feels grainy.
 
J

Jim

Guest
On 31 Dec 2005 04:24:18 -0800, "yoramf" <[email protected]>
wrote:

>Hi,
>
> I read that XTR V-brakes (M960) has "self lubricating bearings". Does
>it mean that these bearing need no maintenance (cleaning/ lubricating)?
>
> What puzzles me, is that after a ride in muddy conditions, I noticed
>that one of the brake arms was seized. It looked as if the bearings of
>that arm were seized. After playing with the arm, it got loose, but now
>the movements feels grainy.


Everything needs maintenance. Take them off, clean and lubricate
them. I have XTR V-brakes, nice but still need normal servicing.
Grease seems to work OK, haven't had problems.

Jim
 
Y

yoramf

Guest
How do I loose the bearings ?
Do I need special tools ?
Are these regular ball bearings or thrust bearings ?
And last but not least - what is the "self lubricating" if I need to
lubricate them from now and then?

Thanks,
 
M

Michael Dart

Guest
yoramf wrote:
> Hi,
>
> I read that XTR V-brakes (M960) has "self lubricating bearings". Does
> it mean that these bearing need no maintenance (cleaning/
> lubricating)?
>
> What puzzles me, is that after a ride in muddy conditions, I noticed
> that one of the brake arms was seized. It looked as if the bearings of
> that arm were seized. After playing with the arm, it got loose, but
> now the movements feels grainy.


The trick is getting to the bearings. They are between the "sleeve" that
goes over the brake post and the arm. There is a rubber boot protecting
them and under that on some brakes is a nut that you can dissasemble the
bearings with though on others the sleeve is flared to hold everthing
together. Sometimes the best you can do is hose them off with spray
solvent and relube with a needle gun.

Mike
 
R

Robin Hubert

Guest
yoramf wrote:
> Hi,
>
> I read that XTR V-brakes (M960) has "self lubricating bearings". Does
> it mean that these bearing need no maintenance (cleaning/ lubricating)?
>
> What puzzles me, is that after a ride in muddy conditions, I noticed
> that one of the brake arms was seized. It looked as if the bearings of
> that arm were seized. After playing with the arm, it got loose, but now
> the movements feels grainy.
>


www. shimano.com exploded view http://tinyurl.com/89xa8 Oh, you'll
need Acrobat Reader.

Their "service instructions" offer no service advice other than
installation, adjustment, and pad replacement, so all we have to go by
is the exploded view and some good sense.

I'd say you washed a bunch of grit into your brake and washed lube out.
You need to flush the thing with solvent and lubricate it by drizzling
in a bit of oil. Make sure you're working the thing while flushing and
lubing.

Many years ago I ran these brakes (952?) and, if I recall, you cannot
open the bearing unit. The exploded view reflects this. I'm pretty
sure theirs alot of press-fitting going on, and not meant to be
disassembled/reassembled by normal means (read, "consumer"). The "self
lubricating bearings" are probably bushings, aka plain bearings. The
only thing you can do is add a drop or so of oil every now and then and
work it in, as you should on the other rotating bits in the "parallel
push" parallelogram as well. I'd go by how they feel without the cable
attached (smooth?).

There is no movement, btw, between the brake and the post, so no worries
there ... just a light smear of oil or grease to keep corrosion away.


Robin Hubert
 
way too much speculation and not enough solid information.

yoramf....you'll need a 15mm and 13mm cone wrench. as well as a 5mm
hex key and something to catch lots of small bearrings.

lift up the rubber boot that surrounds the 5 mm bolt that fixes the arm
to the brake post.

slip the 15 and 13mm wrenches in there and loosen the two nuts. it's
basically like a loose ball hub. if you're unsure of this
description....get it to a shop.

remove the 5mm bolt that fixes the arm to the boss....remove the arm
from the boss. gently pry up the notched aluminum ring that surrounds
the base of where the 5mm bolt is seated.

once that's off.....you can remove both the 13mm and 15mm bolts. you
then have access to everything inside.

be very careful to note the orientation of things. it's easy to break
the plastic cages or install the races backwards.

there are a lot of places and corners for dirt to hide. i've had many
riders open these brakes up...not take enough time to clean things
thoroughly....put it back together (which takes quite a while with all
the small parts in there) only to find out that that the bearings are
still gritty.

my advice to you is....take your time......and make sure things aren't
just wiped down but _actually_ clean. it'll be all for naught if you
aren't thorough.
 
Y

yoramf

Guest
Thanks to all of you.
Since these brakes are brand new, I am now trying to find replacement
and return the faulty brakes to the shop I bought them from.
If I can't find a replacement, I assume I will need to work on the
bearings. I will start with hosing oil into the bearings. If that
doesn't help, I assume I will give it to a shop to take it apart, clean
and re-grease - or do it myself.

Cheers.
 
W

Werehatrack

Guest
On 31 Dec 2005 04:24:18 -0800, "yoramf" <[email protected]>
wrote:

>Hi,
>
> I read that XTR V-brakes (M960) has "self lubricating bearings". Does
>it mean that these bearing need no maintenance (cleaning/ lubricating)?


If they are sintered iron or bronze, the bushings in the arm pivots
could, under ideal conditions, operate without relubrication at rated
load indefinitely in theory. However, as most such bushings are not
used under ideal conditions, this is something that a wise engineer
will *never* tell to the marketing people. Marketing types tend to
misconstrue any such statement as being equivalent to "maintenance
free", which it isn't, even when it's applicable.

> What puzzles me, is that after a ride in muddy conditions, I noticed
>that one of the brake arms was seized. It looked as if the bearings of
>that arm were seized. After playing with the arm, it got loose, but now
>the movements feels grainy.


Yup. Dirt in the bushings, which must be cleaned out. If a stripping
cleaner is used (either a water-based degreasing cleaner or any
solvent), the bushing will be dry, and should be oiled. Hint: You're
unlikely to get all of the grit out without removing some or all of
the existing lubricant as well...
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
Y

yoramf

Guest
Okay, now I am convinced that I may need to do some maintenance on the
bearings (I was unlucky to need this after one ride). So do I really
need to go through all the taking apart procedure (I really would like
to avoid that - as there are many plastic parts), or can I do it from
the outside ?. Or would it be enough to just loosen the two nuts that
hold the bearings in place ?. I don't mind taking the brakes off my
bike.

BTW, I am sure I read someplace that the M960 has Thrust bearings. Does
it mean they need other treatment than regular ball bearings?
 
W

Werehatrack

Guest
On 2 Jan 2006 03:58:33 -0800, "yoramf" <[email protected]>
wrote:

>Okay, now I am convinced that I may need to do some maintenance on the
>bearings (I was unlucky to need this after one ride). So do I really
>need to go through all the taking apart procedure (I really would like
>to avoid that - as there are many plastic parts), or can I do it from
>the outside ?. Or would it be enough to just loosen the two nuts that
>hold the bearings in place ?. I don't mind taking the brakes off my
>bike.
>
>BTW, I am sure I read someplace that the M960 has Thrust bearings. Does
>it mean they need other treatment than regular ball bearings?


Before you open up the main pivot bearing, try thoroughly cleaning the
junk from all the linkage pivots; I'd pull the wheel (to keep from
contaminating the braking surface) and then have at it with whatever
was at hand. The main pivot is supposed to be sealed against getting
major crud inside, but the linkage isn't; as a result, it's likely
that mud in those other pivots is making the noise and causing the
stiffness. Just hosing it off with water, working the junk out,
drying everything and then oiling the pivot points may be enough to
get the job done.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
M

Michael Press

Guest
In article
<[email protected]>,
"yoramf" <[email protected]> wrote:

> Okay, now I am convinced that I may need to do some maintenance on the
> bearings (I was unlucky to need this after one ride). So do I really
> need to go through all the taking apart procedure (I really would like
> to avoid that - as there are many plastic parts), or can I do it from
> the outside ?. Or would it be enough to just loosen the two nuts that
> hold the bearings in place ?. I don't mind taking the brakes off my
> bike.


Use a penetrating lubricant such as LPS2 to flush it.
WD-40 is often recommended, but it leaves material behind
that turns sticky. If you can, loosen the retaining
nut(s), without disassembling to allow free flushing.


[...]

--
Michael Press
 
Y

yoramf

Guest
I couldn't stand it anymore, and I had to take it apart and look
inside.
Well, the bearings are really small (about 1mm in diameter) and being
hold by a retainer unit. I think it is made from some kind of plastic.
There are two such units one on each side (front and rear) of the
pivot. When you take it out the retainer unit will hold the small
balls. The catch is that in order to remove all the dirt, you need to
remove the shim that is attached to the retainer and holds the balls in
place. I did it, and almost lost one bearing balls.
After cleaning everything and applying some grease, I reinstall
everything back. Now its works like new (actually it is new). Since I
don't have the special keys to work on the locking nut, I hope it will
not get loose.
Bottom line, these brakes are not meant to be serviced on the bearing
level. No wander Shimano don't provide the bearing details on the
exploded view of the XTR v-brake system. Unlike for instance, the Dura
Ace brakes. Note also, that now that I know how it is built, there is
no chance you can push grease inside. The best you can do, is use oil.
If dirt got in, you are screwed as I was.

Cheers,