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How To: Brake Caliper Rebuild

39K views 113 replies 44 participants last post by  siq75 
#1 · (Edited)
Rebuilding brake calipers should be done every year, whether you ride track or street. Track bikes go through pads quicker, so they accumulate more brake dust. Street bikes get dirt, water, salt and all kinds of other grime in the brakes. Thoroughly cleaning will not only make your brakes work better, but your pads and discs will wear more evenly when the pistons aren't obstructed by a bunch of shit.

It's only slightly less messy than a fork rebuild, and brake fluid is bad stuff so this is probably the nastiest job you can do. Make sure you have plenty of rags and good nitrile gloves.

This was done on my SV650 with Tokico calipers, but the procedure is the same for 06-08 Daytonas and similar to 09+ (I'll get to that). Here we go!

Drain the brake fluid, preferably with a Mity-vac or similar to get as much out as possible.


Disconnect the banjo bolt, but make sure you have rags and/or a bottle handy to catch fluid because it's almost impossible to get it all out. No matter how much you shake and dance, etc etc...


The brake lines are free; I like to wrap them and hold them high so they don't drip on my garage anymore.


Loosen but don't remove the pad pin (Daytona only has 1 bolt in the middle). It's important to use a good, quality allen as these bolts seize easily and they can be torqued tightly considering how small they are.

Next, remove the big caliper bolts that hold it to the fork leg, again using a good allen. The caliper will now come back off the disc. Be careful not to tilt the calipers upside-down or you'll spill a bunch of fluid.


Pull out the pad pins and you'll have 2 pads per caliper (I have 4) and the anti-rattle clip (the silver thing in the middle). The clips aren't necessary & I've never used them on my track bikes, but you can do whatever you like.


Tilt each caliper into a bottle and drain as much of the fluid as you can.


For 06-08 2-piece calipers, it's a lot easier if you split them, so loosen the bolts that hold them together. My brakes have 3 bolts each. They're torqued down pretty good so I put them back on the fork leg to get more leverage. You could also use a vise with soft jaws if you're careful.


Now you'll have 2 halves:


The pistons need to come out now. My preferred method is blowing compressed air into the fluid passageway, but make sure you have a rag held tightly over the pistons so they don't go flying into your face. Make sure you're wearing goggles too because you'll probably get a little spray. Plug all the holes except one and blow away. You'll hear a pop when each piston comes out.

For 09+ monoblocs, you'll have to do this as one piece. I suggest putting a block of wood between 2 of the pistons and just working on 2 at a time.




You'll notice 2 rubber seals in each cylinder. Those need to come out, but be careful if you're going to reuse them. I pulled the old ones out with an X-acto since I'm replacing them anyway. A dental pick would work well too.


Now you can go about actually cleaning everything. If you're spoiled rotten, you have a sonic cleaner and you can just stick them in for a while. If you're like me, you need to just scrub away. I used a rag and some WD-40, but you can also use Simple Green, brake cleaner, or pretty much any other de-greaser. Once I got the top layer of grime off, I polished everything with a Dremel's brass brush attachment to make it all shiny again. Make sure you get in the seal grooves too because they can leave behind black stuff. Also clean the pistons so they slide easily. Before & after:


All ready for reassembly. Put a light coating of new brake fluid or red rubber grease on the seals & pistons to lube them. Put them back in just with your fingers.


Put the halves back together, then the pads, mount it back on the fork legs & reconnect the brake lines. The banjo bolt's washers should be replaced whenever you take the bolt out. Torque everything to spec, bleed the brake system and ride! (don't forget the wheel if you've removed it...)
 

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#4 ·
oh man! Thanks for this, Paul! I was so hesitant on even PEEKING at what calipers could look like on the inside...now I'll totally be doing this!! :thumbup:

Do you think any of the squishiness I'm getting could be removed with clean-up? Or Are you thinking it'd be from air at the Bleeder?

Thanks again! :bowdown:
 
#6 ·
Do you think any of the squishiness I'm getting could be removed with clean-up? Or Are you thinking it'd be from air at the Bleeder?
Unfortunately, it sounds to me like you're getting air in through one of the bleeders. Rebuilding is really for preventing the pistons binding. It sure as hell never hurts to have clean brakes though!

Do you need to clean the discs at all? Brake cleaner, Scotch Brite?
I had to clean mine because the fork oil was EVERYWHERE. Soaked them in brake cleaner, then did some fine sandpaper since I put in new pads, then more brake cleaner. Otherwise, discs are self-cleaning and don't normally need anything unless you change pads.
 
#12 ·
Nice how-to!

One important thing Id like to add.... I would strongly recommend NOT using any grease to install the seals or pistons. A good coating in fresh brake fluid is all you need. Brake fluid rubber parts are usually NOT compatible with petroleum products!
 
#17 ·
I would strongly recommend NOT using any grease to install the seals or pistons. A good coating in fresh brake fluid is all you need.
Yeah I found it a bit odd that some people recommended the red rubber grease. A little bit would have to seep out and I can't imagine that doing anything but harm in the fluid passageways.

In the shop manual I don't see a torque value for the bolts that hold the caliper together. Do you know what it is?
24nm
 
#14 ·
i love how no one probably ever thought of doing this for YEARS on their bike, and now with the how-to everyone one will....

hopefully we're all as adept as Paul and it wont be a season opener of 675s flying off of Turn 1 everywhere :whistle: :laugh:
 
#18 ·
"Rebuilding brake calipers should be done every year, whether you ride track or street." [MGFChapin]

Very good advice. If you only bleed new fluid through, you cannot get rid of dirt and "crud" behind the pistons.

Just a heads up, remember to replace the small rubber seal between the two caliper halves as well, preferably with a new one. A normal "O-ring" will not work here, as the seal has flat or "square" edges.
 
#27 ·
Well first off , dont buy them from the dealership unless you want to "waste" your money.
The prices the dealership gave me for a sealkit was insaine!
I found this site and layed and order on some caliper seals that are genuine Nissin for 23 Pounds for each caliper!
Great service and fast shipping!

http://www.triumphparts.gbr.cc/www.triumphparts.gbr.cc/info.php?p=2&pid=2350827&ack=9

// Simon (sweden)
Thanks for the heads up. I'd prefer to buy from a vendor in the USA though, and considering 2 out of 3 dealerships closed their doors this past year, I'm willing to pay a few bucks extra to help keep the one and only Triumph dealer in my area in business.
 
#25 ·
Btw does anybody know where I can get the seals for this on this side of the pond?
 
#28 ·
Well I'm in more of a lake honestly. Maybe I'll just see if I can get some when I go to Japan later this year.
 
#29 ·
Thanks for this!!!!!!:bowdown::bowdown:

I'm not very mechanical and i just got everything taken apart, now my questions: I saw some talk about replacing the various rubber pieces inside the piston and the little tiny one between the caliper. Is it absolutely required to replace these? will WD40 damage the rubber in anyway? This is for my track bike and I'd hate to be going down the straight at 130 and my brakes fail lol!

Thanks again to everyone who does a "How to" I've learned a lot :notworthy:

PS i have not removed the rubber pieces from inside the pistons
 
#30 ·
I'm not very mechanical and i just got everything taken apart, now my questions: I saw some talk about replacing the various rubber pieces inside the piston and the little tiny one between the caliper. Is it absolutely required to replace these? will WD40 damage the rubber in anyway? This is for my track bike and I'd hate to be going down the straight at 130 and my brakes fail lol!
No, it's not absolutely required to replace the seals, I just recommend it. So you want to clean everything with WD40 but you're leaving the seals in? WD40 won't damage rubber, but it will bypass the seals and displace the brake fluid back there that acts as lubricant. You don't want that. It's OK to clean everything with WD40, but remove the seals first.
 
#33 ·
When I pulled mine, they appeared to be in perfect condition.. My dad happens to have a very cheap air compressor and the seal on the bottom side failed on me. Can't say anything for the piston seals, yet.
 
#34 ·
Great write up. I was trying to find replacements for the bolts that hold the two caliper halves together. Or is it not necessary to replace these? Also any other place to get piston seals and the seals between the calipers?? I tried bikebandit with any luck, other than piston seals.
 
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