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How to service XTR V brakes.
I couldn't find much on this so I thought I would share what I know. I bought a pair of XTR 960 V's from ebay for my polo bike build, that were not very smooth and I wanted to fix that. It's a good idea to keep one brake together for reference. Here's what I did:
First lift up the rubber cover. The two aluminum nuts are now visible. Next remove the top jam nut by holding the lower nut with a 17mm cone wrench, and use a 14mm cone wrench to loosen it. By unscrewing the top jam nut, it will lift the top of the parallelogram off, which is a press fit piece. Swing the parallelogram out of the way and remove the bottom nut.
The bearings are a two piece set, one having the captured balls and one race, and the other race. Disassemble the brake keeping the two pieces of the two sets of bearings together
(each bearing and race should remain a matched set).
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Now its time to clean the parts. For the small parts I use a tea ball and swish it in a jar of mineral spirits. The rest of the brake parts I used a Q-tip and paper towel.
Once the parts are clean and dry the bearings need to be greased with whatever grease you would like to use. A small amount is enough to lubricate the small bearing balls.
Start the reassembly by sliding one race and one bearing on the brake base. Next insert the base into the brake arm. Then set the other bearing, then race into the brake arm
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Good post.........
Out of interest, how much play is there on the axle the actual brake pad mounts on to? There's loads on my old bike and I wasn't able to source a re-build kit in GB (product too out-of-date I think). If you had bad play how did you get around it?
Thanks
Using yesterday's technology, to create tomorrow's problems, today.
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Spin the larger bottom nut all the way down finger tight. Snug it up with the 17mm cone wrench but not tight. The base should spin freely under the brake arm. Now install the smaller nut ( relief cut facing the bottom nut). Tighten it against the bottom nut while holding it from spinning with the 17mm wrench. Keep in mind these are aluminum nuts, so err on the lighter side of torque. Slide the rubber boot over the parallelogram. This part is the only tricky part and is where the brake for reference is helpful. Lift the parallelogram over the brake and align the notches. The fit is a press fit so I used a small plastic bar clamp to lightly press the parallelogram onto the brake. Don't go overboard, cause if it's not completely seated, it will press on the rest of the way when it is mounted to the bike. Replace the rubber boot over the nuts. Wipe any excess grease from the brake.
Make final bearing adjustments (preload) when the brake is mounted on the bike. It should move very freely but have no play.
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 Originally Posted by Major Clanger
Good post.........
Out of interest, how much play is there on the axle the actual brake pad mounts on to? There's loads on my old bike and I wasn't able to source a re-build kit in GB (product too out-of-date I think). If you had bad play how did you get around it?
Thanks
Thank you.
There isn't any play in that pivot. I believe I got lucky with these, cause they don't look like they have had a very hard life.........yet.
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i like my v brake setup as well , however later on i might swap out to a front disc brake.
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Nice post! Most people don´t know they are serviceable.
I did that once to my xtr´s too..so much work I didn´t do it again 
I believe these are the only V-Brakes you can actually repack, very nice brakes.
Thanks!
"Blessed is the man who, having nothing to say, abstains from giving us wordly evidence of the fact." George Elliot
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Super. Very well presented and informative.
Regarding the brake blocks - if not used for a few years they (canti / v brake) blocks get hard. If used like that would they damage the rim ? Would appreciate your comments. Thanks. .
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They used to sell shim kits for them as well.
I wonder if it would be easier to spray them out with brake cleaner, heat up a little grease and dip them in there then clean it off the outside?
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This is not a difficult task. It took me about two hours total to do two pair, take pictures, and write this thread. Granted, the brakes were not on a bike yet.
Jack- if by blocks you're asking about the brake pads, I've never seen any get hard enough to damage a rim, they just don't work well.
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 Originally Posted by steeneriam
Jack- if by blocks you're asking about the brake pads, I've never seen any get hard enough to damage a rim, they just don't work well.
steeneriam, thanks. Yes, I mean brake pads. I have started using a bike that was un-used for about 5 years and I find the brake pads have got hard - when you dig them with your finger nail they do not give at all. Besides less braking performance I was wondering if they will wear / damage the rim ? I live in Sri Lanka and good quality replacement pads are not available here - have ordered some but they will take at least 2 weeks to arrive.
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Can anyone tell me what the positional relationship between the "parallelogram" and brake in aligning the notches? I do have the one set still assembled, but I am not getting the same travel in both (the overhauled, and the reference sets). What mark or reference would one use if he did not have a reference set? Also, is the blue loctite?
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I miss my 1st gen XTR v-brakes. Those plus ceramic Mavic rims and ceramic specific pads were fantastic, even in the wet.
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Fantastic write up, cheers for that.
Adding some keywords:
BR-M950
BR-M951
notchy
stiff
brinelling
detents
misc ramblings:
Upon opening them up, you may find that enough sand/grit/crud has entered the bearings to cause the feel of detents or brinelling, or that a previous rebuild job has left the nuts overtightened.
If the grit intrusion is severe, removing the bearings from the cage may be necessary.
Suggestion:
Count the ball bearings before disassy.
Work in a water-filled container (e.g. shoebox size or such) of sufficient size and have a magnet present therein. Working in water is to prevent the ball bearings from flying throughout your workspace. Use the magnet to pull any trapped ones from old grease, then to collect loose ones fallen to the bottom of container.
You may choose to replace the ball bearings after lightly oiling the cage, or not. Picking them up one at a time by jamming them under your fingernail seems to work, and allows for a tactile release mechanism. Grease applied subsequently may likely cause the bearings to climb out of the cage. Work slowly and deliberately. Toothpicks better than Q-tips.
Once a single bearing is cleaned and rebuilt, you should be able to counter-rotate the metal washers that sandwich the cage. (yes, tough with big hands) You will feel any remaining grit. If present, strip and redo (reclean) that bearing unit until you feel no more grit.
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