Brake Caliper Overhaul...

[Damon]

I didn't know whether to put this here or show and tell

This is a quick thread to show people how easy it really is to overhaul their brake caliper.

Basically, I got these calipers off the crash damaged Fireblade my uncle and I are rebuilding. They were in a sorry state and hadn't been looked at in a long long time. Saying that however, the pads had recently been replaced before the crash. When I took the calipers off the blade they looked like this...

https://img38.imageshack.us/img38/7120/img0417wt.jpg

https://img200.imageshack.us/img200/1116/img0418uk.jpg

First thing to do before any cleaning is to remove the pad retaining spring and pins. On this caliper you remove the pins with an allen key, however, alot of calipers I have overhauled use small R clips instead. Each caliper is different. Once removed, the pads should fall out, giving you your first glimpse of the pistons inside.

https://img18.imageshack.us/img18/9844/img0419lu.jpg

[Damon]

Now its time to start cleaning. I used my Ultrasonic cleaner for the first time on a bike part and it came up great. I would normally use an old toothbrush and brake cleaner to clean the calipers but the ultrasonic cleaner is just that much better. It's a lazy way of cleaning.

https://img411.imageshack.us/img411/6308/img0420ov.jpg

https://img251.imageshack.us/img251/6049/img0421o.jpg

https://img169.imageshack.us/img169/9175/img0416f.jpg

As you can see they have come out fairly clean. I quickly ran over everything with a toothbrush to get rid of any stubborn dirt.

Next on the agenda was to split the calipers. On the blade the caliper bolts were torx star bolts. This is the first time I've seen caliper bolts use this method (maybe it's a nissin thing). Usually its either allen bolts or a 12mm hex bolt. Like I said, every caliper is different. I haven't got any pictures of removing the bolts but it was a case of removing every bolt (4 on each caliper). Once these were removed, the caliper will just split into 2. Take care not to lose the O ring seal on the corner of the flat making surface on one side of the caliper. Take this out and keep to one side. If it is split or cracked, replace. If it looks ok, then its fine to use again. Once split, the calipers should look like this.



https://img694.imageshack.us/img694/275/img0425vb.jpg

Next give the pistons a clean , making sure all the crud is removed from around the seals. Push them back into the caliper once cleaned. Be careful though, as brake fluid will squirt out when the pistons are pushed flush.

[Damon]

All the bolts were rusted up and covered in general crap/salt. They needed cleaning and polishing. I did look at replacements but going down that route can get expensive very quickly.


https://img5.imageshack.us/img5/3741/img0433z.jpg

What I decided to do was to put each both into my drill press and using selection of wet and dry (240 grit, 800 grit and 1200 grit)

https://img6.imageshack.us/img6/5194/img0435ly.jpg

I proceeded to "sand" the heads of the bolts. I put the bolts into the chuck and set the drill to a slow speed. Using a square of sandpaper I wet the paper and pressed it against a moving bolt until I was satisfied that the bolt had been roughed up evenly. I then proceeded to move to the 800 grit, using the same method again, finishing off with the 1200 grit for a bit of a polish. The results came out great. See for your self, Much better. If you dont have a drill press, a normal drill could be used if secured in a clamp/vice.

https://img682.imageshack.us/img682/6771/img0443ld.jpg

https://img443.imageshack.us/img443/8106/img0432k.jpg

[Damon]

Now its time to inspect the brake pads. As I said earlier, the pads in the fireblade were pretty new and only needed refreshing. I would however recommend that if overhauling your calipers, you should really change the pads too. They are cheap to change and well worth doing. What I did to refreshed the existing pads was to sand the copper back of the pads with some 120 grit wet and dry. This is to allow correct heat transfer to stop the pads from overheating. Once the backs were nice and shiney, I moved onto the pad itself.

I glued a piece of 120grit paper onto a flat surface and rubbed the pad front (the bit that makes contact with the disc) onto it until the whole pad surface was scuffed. This is to make sure the pad surface is flat, thus stopping uneven wear on both the pad and disc.

https://img297.imageshack.us/img297/6849/img0438s.jpg

I then put both sides of the caliper and the pads onto the grill door to allow any excess water to evaporate.

https://img411.imageshack.us/img411/8497/img0439s.jpg

https://img25.imageshack.us/img25/786/img0440xe.jpg

[Damon]

Finally, its time to put everything back together. Make sure you refit that rubber O ring seal that you put aside safely earlier. Then refit the caliper bolts using a small amount of thread lock on each bolt. Make sure each bolt is tight enough and that the o ring seal has seated perfectly. If it hasn't the caliper wont work full stop.

Next to refit the pads. Put a smidge of copper slip (high temp grease) on the back of the pad but make sure not to get any on the pad surface itself. Push the pads into the caliper and then refit the pad retaining spring and pins. Check everything is aligned (pushing the pistons back into the caliper as I said earlier helps) and then tighten up the pins. Push each pad against the caliper piston and refit to the bike.

https://img34.imageshack.us/img34/8753/img0431xo.jpg

https://img132.imageshack.us/img132/4770/img0444dl.jpg

https://img35.imageshack.us/img35/3469/img0446mq.jpg

https://img708.imageshack.us/img708/807/img0452rq.jpg

And there we have it. Overhauling a caliper is really a quite simple prosess that consists of mainly cleaning. Next time I have to overhaul a caliper that needs new seals I'll do a specific seal replacement thread as I didn't cover it here. If anyone has any questions, feel free to post on this thread or PM me. Hope you enjoyed this basic write up.

[Darth]

*edit - read last paragraph again,
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Harold_Shand wrote: I suppose it's like anything, you get your fingers burned when you start out, you learn from it and eventually become a complete arsehole about the whole thing.

[Damon]

[Blackwolf]

Proberly a stupid question, how did you "expose" the pistons?

Tempted to do this with my SP1, and i guessed you put the torx bolts in tight first then added pads ect..

Im compitent enough to do this, its just slightly nerve racking at the same time
Just thought of something, even after using break cleaner, do you not leed to re lubricate the seals with anything?

And as for the torx heads.. its just a Nissin thing..
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Current: Ducati Multistrada 1200s

[neil.]

If it's anything like on my YBR brake caliper, you'd expose the piston(s) by pumping the brake lever which makes them pop out a bit more with every pump, then when you're done, push them back in by hand or with a bit of wood etc. The thing to watch out for is if you've topped up with brake fluid with worn pads as when you push pistons back in, you'll need to siphon some out of the master cylinder reservoir with a syringe. Also the oposite to this is not having enough fluid in the system and as you expose the piston, you get air in the line.
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CBT February 2008 | A2 June 2008 | Yamaha YBR125 (written off) | Honda CBF125 (current)

[Tim..]

[Damon]

[ms51ves3]

If the pistons aren't seized, the little 12v car compressors/tyre pumps work to pop pistons out. This means the pistons won't fire out at a stupid speed. You can get them for about £5.

[TUG]

Or you could just remove the pads and pump them out with the hydraulic force from the brake fluid and lever action?
With a spanner inbetween them where the disc groove is. Split then pull out even seized calipers are a peice of piss when you know how.
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Haz ER-5, innit!

[Damon]

[lonner]

nice thing about nissins is they dont tend to corrode in the seal grooves like the inferior tokicos do as there always a piston out and a scrape job

but you done a superb job on them and ill be looking into this ultrasonic thingy too

fitted these to my 12r as the 6pot tokicos were a load of crap and there fantastic

https://i495.photobucket.com/albums/rr319/SP2Riley/DSC02954.jpg

[ms51ves3]

[el_oso]

never thought about using them ultra sonic cleaners before on bike stuff.

"mum, just borrowing your jewellery cleaner. thanks"

can imagine a scenario previously when i put my cylinder head in oven to dry it.

"neil, why is your engine in the fvcking oven!"

"its drying. i couldn't be bothered to hold your hair dryer over the engine"

"you used my hair dryer!"

or

"neil, why are you taking my nair varnish"

"fill the pits in my fork legs"

conclusion - women's beauty products work well for repairing bikes
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Duke 390
Previous: '05 XR125L | '96 XJ600S Diversion |'05 Suzuki GSXR1000 | '05 Honda CBR125-R | '97 YZF 600R Thundercat | '11 Honda CBR250
Car: Jeep Wrangler 4.0L

[Serendipity]

I just did a minor overhaul on exactly the same callipers on my Blade. On the way home from work on Friday night the brake started binding. It didn’t bind for long, but it reminded me that they needed attention.

So on Sunday I popped the pads out and cleaned up the pistons pretty much as described here. However I left all the lines attached to avoid the pain of bleeding them again. After all this wet, salty weather I wasn’t surprised to find that one of the pads was actually welded to the calliper with a thick crust of crud and corrosion. Took a while to get a couple of pistons moving. I blocked the movement of the working pistons with a toothbrush handle to get the reluctant ones moving. The pistons on the 954 have some sort of non stick coating so I find that they come clean with a bit of toothbrush and paper towel action.

Once all the pistons are clean I tend to slide them in and pump them out again several times to get them moving really smoothly. By that stage I had trouble pushing them back in because the others would pop out as I pushed one back in. Finger pressure is enough to get the Blade pistons back in. On my old CBR600 I’ve had to resort to bits of wood and G clamps before.

I washed everything down with isopropyl alcohol, copper greased the appropriate bits of the pads and put it all back together. The difference this week has been amazing. So much more power available and barely need to tickle the lever to stop the bike on its nose. Well worth an hour of my time.

I’m quite tempted by this ultrasonic malarkey. What sort of size machine have you lot gone for?
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2016 CBF1000F - Commuter heaven | 1994 CBR600FR - Awaiting defibrillation

[Noxious89123]

What liquid do you use to submerse the parts in, in an ultrasonic cleaner?

I was surprised you put the brake pads in there Did you put the caliper halves in there too? They're very clean!
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'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[Billing]

I think water is used, but not entirely sure

Damon, when you refitted the calipers did you renew your banjo washers or not? I've been in the awkward position of having new lines, but no new washers, so re-annealed them with a blow torch, they didn't leak so I proclaim it a success!
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'84 TS50X, '91 TZR125, '89 CBR400RR, '91 VFR400R NC30, '98 R1
"Hey copernicus! Why don't you navigate yourself to the back of the line with your feet and stand there with your shit."
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[Phoenix]

By putting the pads in an ultrasonic cleaner do you not risk damaging the bond between the pad material and the backing plate resulting in possible pad failure?

[Blackwolf]

So is it a relivatly simple job to do?

The more i take my bike apart the more stuff i need to replace...

pads discs...
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Current: Ducati Multistrada 1200s

[DazHornet]

so can someone explain what liquid you put in an unltrasonic cleaner??

and where can they be purchased from?

[Damon]

My ultrasonic cleaner is an old one from when I was tattooing

Found a place that sells them. That is exactly the same as mine

https://www.thetattooshop.co.uk/shop/products/ultrasonic-cleaner-digital.htm

I just used a little ultrasonic cleaning agent + water in there. The cleaning agent is basically fairy liquid with a new name




Putting the pads in there is fine as the ultrasonics is no way near powerful enough to split the pad from its backing + there are no real chemicals in there to harm the pad.

Yeah caliper halves went in there too. Just remember you are really just cleaning with water and a bit of detergent. As long as you get all the water off the part you are good to go.

R.e copper washers. Yes, I did replace the washers. I bought a big box of copper washers a while ago and they have come in handy a few times now. Never tried the anneal trick. For the price of a new washer, its well worth just replacing.

[Damon]