Rebuilding calipers?
 

Anybody got any tips?,
Mine are jammed on and need a good rebuild,the seals are probably ****ed on them,whats the best method,toothbrush and ?
THanks
Darren :D
Btw merry xmas!

Re: Rebuilding calipers?
 

I wouldn't waste my time, you might find that after you fiddle around cleaning and rebuilding for several hours that the calipers are worn beyond rebuilding

my dealer ate several hours of labor doing that for me trying to save me money, new calipers only cost 2 hours of labor

if you can leave them coupled to the bike and pump them out ( you may need to top up your resevoir )

A trick here to get stubbon pistons moving is to leave the caliper in position but take out the pads on the half of the caliper that is stuck then the free side will not pump out first ;)

once out you could use a rotary wire brush in your drill i use a zip wheel in a grinder if there terrible though with big pits you need new pistons but hey its worth a try

either that or 600 wet and dry and clean them up once clean grease well with rubber grease
( this type of grease doesn`t degrade the seals any ;) )

the first method is more a last resort really but id sooner take a caliper to bits and repair it for an hour than replace it for myself

for a customer id replace it that way down the road any problems and you dont get called if your so called repair suddenly goes wrong its down to the new part and not you :D

if they are silly money like ive done in the past i will overhaul them though

Just buy a rebuild kit from Fowler ins Bristol(mail order) Comes with pistons and seals, Take out pistons (Use a set of 5 holes..or waterpump pliers...the ones that you can open up to a huge span) dig out the seals, thouroughly clean all the seal recesses with a pick/scrapper(not a srewdriver) or a softish wire brush on a dremmel. clean the caliper all over...personaly id replace the beed nipples with S/S items from HEL.

Then thoroughly rinseout the claiper with clean brake fluid, empty, and dry (Get a can of air duster from an electrical shop) then place the calipers indoors near a radiator to make sure that they are dry.

Rebuilding.

Put the seals in, then dip you clean finger into some clean brake fluid and rub over the seals. Dip the clean pistons into the clean brake fluid and insert them very carfuly into the holes and push both fully in. Undo bleed nipple slightly, and fill the cliper through the banjo hole, nip up the bleed nipple. Fit back to bike using new copper washers and tighten the banjo to 23ftlbs.

Repeat for other side.

Bleed brakes in one of the many ways that there are.

When re assembling, the thing is to be clean, spotlessely.

excellent post,
thanks alot :D
Dar

My tips (from personal experiance of damaging calipers!!!!) are with stuck ones is to take the caliper off - then the pads out, then lighlty pump the brake until one of the free pistons are at the top, and then put a g clamp on that one to create pressure to pop out the other then they should just wiggle out.

Chances are they may just need a good clean and you can save yourself a lot of money, just buying new seals. So before using pliers etc. and risk scoring the pistons do the above procedure to pop both pistons out without damaging them. Then they may just need a clean, new seals and some brake grease. If the pistons are found to be extensively pitted replace them as this will leak brake fluid and can cause it to sieze as well. Ive dealt with calipers and some times it is just a case of clean, new seals, and grease.

Good tip from the guy aboves post - buy new s/s bleed nipples as they can easily be sheared off when they are rusted, and then you would need a whole new caliper!!! (or very tiny helicoil, lol)

surely if you do that, you risk warping your disks?

True but Brakes could save your life. Is it worth saving £30?

not really you only warp hot ones ;) cold ones you bend but you wont bend them they arent that soft


they float aswell to a degree


EDIT ( use your discretion here really seized ones will need like the g cramp method ;) ) this is a quick fix for no tool numptys :D

It is possible to rebuild even some very badly corroded callipers.

First of all I would agree with the suggestion of replacing the bleed nipples. A corroded bleed nipple will only cause air to get in to the system in addition to being difficult to use.

When cleaning out the grooves where the seals sit I would use something wooden or plastic that isn't likely to damage the surface to scrape off some of the worst corrosion and plenty of brake cleaner or WD40 helps also.

When rebuilding I have found that rubber grease rather than a bit of brake fluid works best. Apply it liberally to the seal, the grooves and the sides of the pistons to help keep the air out.

Once everything is back together bleed it the best you can and then hang it upside down overnight which should help shift the air bubbles caught in all the little cornes where they can't get out easily.

Good luck.

Yup, that's what my dealer told me trying to save me money, they'd but the calipers together, squeeze the brake lever onetime and pop the pistons out....

if your calipers are all pitted & corroded adjacent to theseals from winter salt...
don't bother trying to rebuild them, a waste of time

On the contrary, if you've got the time and the inclination the results can be quite impressive. I rebuilt the callipers on my race early/mid season 2003 and they are still going strong.

It may not be worth the amount of effort compared to the cost of buying new callipers or pistons but it can be a very successful operation.

Beleive me, if your rebuilding them cause they have been corroded with winter salt, it is a waste.... once you get the corrosion out, tollerances are too loose, piston pops out..... my dealer lernt the hard way, they ate the cost of thier rebuild attempt. Your race bike prolly didn't have much corrosion

Before we get in to a p**sing contest to see who has the most valid opinion it is worth reminding everyone that we have all had our own experiences on the subject and they can all be considered, or dismissed, as you see fit.

My race bike had done a couple of years road use and then sat in a breakers yard for a number of months until I bought it. The callipers were a mess but with a lot of elbow grease and determination they were brought back to be some of the best brakes in the race paddock.

For the sake of a fair argument I know a number of racers, or their mechanisms and/or their local bike shop, who opted for the brake fluid on the seals option but many of us found that rubber grease worked far more effectively and reliably. Maybe it had the benefit of evening out some of the corroded surfaces or maybe we just got lucky.

Either way I am just adding to the number of different options put forward by the people on the forum. If you can do the work yourself then new seals and a few hours work is a good investment, if not, then maybe keep an eye out for some callipers from a newer machine that have had an easier life.

+1. I've re-built calipers on bikes 20 years old and other brake parts on vehicles 50-60 years old with good results. If there is pitting then yes, they're trash but since they're always covered in brake fluid and are doube sealed, that's not too likely.
Personally, if the calipers are only ~$100USD each, I'd think about replacing them.

what happens is the corrosion ring works it's way in deeper with worn pads. when you put new pads on, the seals are then backed out over the corroded portion..... I have replaced the front calipers on my SV once and the rear caliper twice

Re: Rebuilding calipers?
 

Righto, without wishing to drag up an old argument, I wanted to get people's opinions on buying new calipers vs. rebuilding old ones. Apologies for the length of the post, but I thought the more detail now, the fewer questions later. :)

The front brakes on my K4 aren't what they used to be. The front left disc rubs ever so slightly when spinning the wheel and consequently the pad is wearing unevenly (although only a little bit). One of the 'R' clips is buggered, although the other is okay. I've not had the pistons out completely in ages (at least 20K miles), but judging by the bit I saw when I pumped them out a bit and gave them a spray with break cleaner and scrape with a steel brush, they are fairly rough surfaced. I noticed one of the outer seals (dust seal?) looked like it was twisted out of shape a bit, but it wasn't leaking fluid and I needed the bike today so I have just put it back together. Whilst the bike has 44K on the clock, I'm not interested in junking it; I will run the bike into the ground and get considerably more mileage out of it before it goes pop and even then I'll probably just put a second hand engine in, so to a certain extent I'm not worried about it "making financial sense" for an old bike.

My riding style and type of riding I tend to do means I don't use the front brakes terribly hard with any sort of regularity. Because of this, it's still on the original pads (which are in surprisingly good nick) and discs although I wonder given the rubbing if the front left disc isn't a little bit worn. Discs wear is within the tolerences (haven't checked the exact distance for about 6K miles, but it was 4.2mm then). The original rubber hoses have yet to be renewed and are due given they are now 4 years old. In terms of servicing, the brakes have been checked twice by a (comparatively) reputable dealership. In addition to this, every time I've had the front wheel out, I've had the pads out, scraped them with a steel brush, sprayed them with brake cleaner and pumped the pistons out as far as I dare without them coming out and cleaned as much of them as I can access in the same way. I've then liberally doused the backs of the pads and the pistons in coppaslip and re-assembled. I have changed the fluid completely twice and topped up & re-bled it once in addition to this.

For personal reasons, I would rather minimise the amount of time I spend in the garage tinkering so if rebuilding takes ages I'd rather new ones, but not at the expense of a hell of a lot of money. Whatever the option I go for, I'll be fitting it all myself. Not wishing to jinx myself when it comes to doing these, but I seem to have the 'knack' of bleeding brakes and have a new mityvac waiting to be used so that shouldn't be a problem, it was more the rebuild itself I was seeking opinions on, rather than the bleeding aspect.

So, given I'm reasonably comfortable working on brakes, what are people's opinions on a rebuild vs. 2 new calipers? What is a ball park for two new OE calipers from a dealership, just the parts, not labour? Anyone got any links to rebuild 'kits' containing the seals/pistons, etc. ideally ones people here have used and rate highlt, as I've had problems with the fit of some pattern seals recently and this makes me cautious about using them on something as important as front brakes!
I've just fitted new fork internals so no gixxer front end swap suggestions please. Likewise, for insurance reasons I don't want to try and fit gixxer calipers or anything like that. ;)

I am tempted that given the need for hoses to be replaced and whatever I do resulting in it needing to be bled, to fit S/S hoses at the same time. More for the fact they'll last the rest of the bike's life and probably cost less than OE rubber hoses, than wanting the extra performance. Opinions?

As ever, TIA, Ceri.

Re: Rebuilding calipers?
 

I've had good results rebuilding calipers with new seals and not replacing pistons.

Obviously knackered pistons are knackered, but rebuilding them with a good dollop of rubber grease prevents the corrosion from occuring. Prevention is better than cure.

I call b0llocks on replacing the calipers. It's worth having a go at rebuilding them. You said your dealer recommended replacement? Well they probably didn't do a very good job of servicing them at previous attempts, if at all.

Re: Rebuilding calipers?
 

Pistons can be pain to get out. I find a compressed airline quite a good way of removing them. I've even used a footpump. You just need one of those conical adapters and shove it in the hole where the hose attaches. A few PSI later and pop. Just watch your fingers as a stuck piston can suddenly shoot out, especially with loads of pressure behind it.

Re: Rebuilding calipers?
 

+ 1, the callipers I have on the 800 are from 1996 and have been rebuilt a few times now...

http://forums.sv650.org/picture.php?...&pictureid=824
http://forums.sv650.org/picture.php?...&pictureid=822
http://forums.sv650.org/picture.php?...&pictureid=821

The pistons will get to a point where they will need to be replaced, mine took eight years (from 1996) to need replacing. Overall the servicing has cost me less than the price of buying new callipers each time, afterall it is the main body of the calliper which is still working 100% to spec and cost the most to replace.

Re: Rebuilding calipers?
 

This thread confused the hell out of me... "Dar bought another TL! And Mike Numbers is back! And so's Bartyboy! And Randy and Donnie have returned from SVR! And I'm still 26! Wait..."

Anyway, since we're zombie-threading, I reuse seals most of the time since I never let my calipers get bad enough to destroy them, but I wouldn't do it on anyone else's bike, it's my decision/risk/responsibility, so I always use new seals on anyone else's calipers. I've bought a replacement rear caliper twice now, because they're so ridiculously cheap- £5 for a caliper with pads, cheaper than buying seals let alone pads. But that's always a gamble of course, I like to buy Busa calipers because they tend to see less manky roads than SVs.

Airline is the correct tool to remove pistons. But they come out rather fast, I once fired one the entire length of my garden... Then decided that next time I'd point it at the ground, and ended up having to dig a piston out of a surprisingly deep hole in the lawn. Bucket of water is good, makes a mess but stops the piston nice and gently, and deals with any fluid too. If you did this sufficiently stupidly, losing an eye would be very easy. And remember compressed air bites...

Re: Rebuilding calipers?
 

Or one of these...

http://forums.sv650.org/picture.php?...pictureid=1033

This is allowed in the house... ;)

Re: Rebuilding calipers?
 

surely buying new ones and then rebuilding the old ones so you have a spare set and time to work on them is the best road to go down. Even if your skint buying new ones and selling old ones to be rebuilt is gotta be worth a shot. Sounds like the best road for Ceri anyway.

Re: Rebuilding calipers?
 

Mmm, that'd depend. Personally I'd just take a closer look then make a call, servicing brakes doesn't take long if you're familiar with it and you have all the bits but if it turns out that you need a seal or (whisper it) new pistons then all of a sudden you have no bike for the duration.

Re: Rebuilding calipers?
 

I've never seen a set of calipers so worn hydraulically as to need replacement, however I've seen several sets worn on the sliders such that the calipers are unusable.
If you do the work yourself, assuming you're able of course, then rebuilding is always cost effective as long as the above is bourne in mind.
If however you're paying a shop to fix them, then replacement might be best - after you've paid for parts and labour a new might not be dearer.

Re: Rebuilding calipers?
 

Also compressed air is not always enough. Unless you have better compressors than me? Have used up to 110psi and failed!

Perfect piston removing tool comes free with the bike.

Re: Rebuilding calipers?
 

I'm working on the assumption here they're already removed ;) But yeah, if they're fitted it's daft not to just use the handy lever provided for pushing the pistons back and forth.

Re: Rebuilding calipers?
 

Forgive my ignorance, but are the sliders the bits of the caliper that the pads slide forwards and backwards on? E.G. The male bit that goes through the holes on either end of the pad (well, 2 on one pad, 1 on the other).

Re: Rebuilding calipers?
 

Yup, and the bores can wear.

Re: Rebuilding calipers?
 

Ah, mine are still nice and snug. I think I'll go for a new set of seals and giving the pistons a really good clean and replace the brake hoses at the same time. I'll have a Haynes, large bottle of new brake fluid, a tub of that magic red castrol rubber grease (which doesn't harm the brake fluid), tub of copaslip, can of brake cleaner, wire brush and mityvac to hand, anything else I need to get or should be aware of before attempting it?

I've got a Dremmel-like thing with a load of attachements, will it be okay to use that to get in the nooks the wire brush can't reach to clean up parts, provided I thoroughly clean all the dislodged dust/carp off with brake cleaner afterwards?

Thanks for all the advice folks, it's v. much appreciated.

Re: Rebuilding calipers?
 

8mm spanner for the bleed nipple.

Re: Rebuilding calipers?
 

Oh yes, sorry, I shoudl have mentioned, I'll have a comprehensive set of spanners, sockets and screwdrivers as well as usual brake-bleeding things such as tubing, old jam jar.

It was more because I'd not had a caliper in bits before, was I going to find I needed some special tool to get the seals out, insert the new ones, or anything like that. Any kind of 'gotcha!' that was likely to reveal itself only once I have the pistons out and old brake fluid all over my lap. :)

Re: Rebuilding calipers?
 

You could one of these from some where like halfords, helps get the stubborn pistons out when the miss' won't let you bring the compressor in the house.

http://forums.sv650.org/picture.php?...pictureid=1033

Re: Rebuilding calipers?
 

Is there a picture missing from that post?

BTW anyone got any recommendations on a particular one of those "reverse G-clamp" like tools for forcing pistons back in/pads apart?

Re: Rebuilding calipers?
 

Personally no, because I don't think pistons should need that much force. If it does then somethings wrong.

Re: Rebuilding calipers?
 

+ 1

Re: Rebuilding calipers?
 

Should be this only.

Re: Rebuilding calipers?
 

"Invalid Album specified. If you followed a valid link, please notify the administrator"

:(

Re: Rebuilding calipers?
 

Oh... have a look in the 800 album on my profile, should be the first image.

Re: Rebuilding calipers?
 

Ta, can see it now. Is there a special name for those sort of pliers if I can't see it on the shelves?