GSX-R brake calliper trouble?

[dirtyred619]

Went to get the speedo sorted this weekend as the last part (or so I thought) of the puzzle to finishing the front end swap. I've had the bike out prior for a little test around a car park and it felt fine and everything was working as it should be.

Magnets were installed in discs already at this stage, so it was a case of fettling a bracket to accomadate the sensor underneath the mud guard and all should be good. So I jacked the bike up on paddock stands and set about the job. Thats when I noticed the the front wheel didn't turn freely and took a little bit of force to turn, great! I'm assuming that one or both of the discs are catching on the pads stopping it from turning freely but not sure what to do about it.

I finished installing the sensor anyway, and as the bike before starting the job seemed ok I decided to have another little ride to test the speedo was working ok, which thankfully it seems to be.

I'm going to unbolt the callipers later when I get chance and test again to make sure it's them (what else could it be really!) but assuming it is them, what can I do about getting it sorted?

[yorkie_chris]

Strip and rebuild, will probably be a load of crap behind seals. Provided you've not put wayyy too much fluid in or owt

[dirtyred619]

Wish I could! Saying that though I have got new pads to go in the front (even though current ones aren't too bad) so will double check the fluid level is ok, kinda hoping it is now lol! But if stripping and rebuilding is something that I could do I might have a go as it's good to know how to do it. Failing that might see how much the garage charges!!

[maviczap]

Yes, mine needed a strip down, just one piston was sticky, but still caused the pads to rub on the disc

[dirtyred619]

Sounds like I'm best getting them done then. I'd love to have a go myself rather than pay £70-£80 at the garage if I can. Is it particularly difficult?

[Nobbylad]

Dead easy - you will need red rubber grease, patience, a couple of hours and a pump with some tubing or a compressor to get the pistons out. If you have a dremmel with a wire brush attachment to clean the crap out of the grooves in the calipers that would be a time saver, if not, tooth picks or something that can pick the crap out without damaging the surface.

[yorkie_chris]

Pump them out using the master cylinder ;)

[dirtyred619]

Just watched this video, http://m.youtube.com/#/watch?v=QY8WWA6E9H0&desktop_uri=%2Fwatch%3Fv%3DQY8WWA6E9H0, is this pretty much the way to do things?(mine are 4 pots though). Think I'll pump the pistons out with the m/c as it sounds easier but would I have to be careful that each piston goes back where it came from or does it not really matter (assuming they're all the same).

[dirtyred619]

Where's best to buy the seals from?

[maviczap]

Wemoto or Robinsons, or your local dealer

[Nobbylad]

You might be able to reuse the seals. When you're done, they should look like this. ...

http://i11.photobucket.com/albums/a161/nobbylad/20130406_203957_3_zps388af7d4.jpg

[dirtyred619]

I'll have a go anyway. Would it be obvious if the seals need replacing, obviously it would be great though if they can be reused.

Whats best to use to clean them up with just brake fluid and an old toothbrush or something else. In the video I posted a few posts back he used very fine grit wet and dry (2500 grit) to polish up the pistons, good idea?

[Bibio]

what front end do you have?

[dirtyred619]

Forks are K1/K2 GSXR1000 and brakes are K2 GSXR750 4 pots.

[Nobbylad]

Brake fluid for the gunge on the pistons and calipers, shouldn't need to use wet & dry, just some kitchen roll or a rag and a spray of brake cleaner should clean everything off. I wouldn't use brake cleaner on the seals, in the past, I've left them to soak in some warm water with a tiny drop of washing up liquid, to soften the salty deposits, then used a toothbrush to clean the grooves of the seals themselves. The caliper seal recesses are probably the hardest bit to clean if they're properly carped up, but with some toothpicks or a dremmel with a wire brush attachment, they come up gleaming. Might be an idea to use some fine wet & dry on the caliper mounting faces if they're particularly grubby.

Deffo get some red rubber grease to wipe around the seals/pistons when they go back in though.

[maviczap]

Brake fluid for the gunge on the pistons and calipers, shouldn't need to use wet & dry, just some kitchen roll or a rag and a spray of brake cleaner should clean everything off. I wouldn't use brake cleaner on the seals, in the past, I've left them to soak in some warm water with a tiny drop of washing up liquid, to soften the salty deposits, then used a toothbrush to clean the grooves of the seals themselves. The caliper seal recesses are probably the hardest bit to clean if they're properly carped up, but with some toothpicks or a dremmel with a wire brush attachment, they come up gleaming. Might be an idea to use some fine wet & dry on the caliper mounting faces if they're particularly grubby.

Deffo get some red rubber grease to wipe around the seals/pistons when they go back in though.

As above, although I read that it's better to clean the grooves in the calipers with a nylon bristle attachment for a Dremel rather that a wire brush attachment.

Makes a bit of sense, as the metal bristles are feckin sharp, and might cut the new seal if there's any bits of bristle left behind after cleaning the grooves.

Wouldn't use wet & dry, but using a green Scotchbrite pad would be better, not quite so abrasive.

[dirtyred619]

All good advice ta, basically if I give it a good going over with brake fluid and a toothbrush it should do the trick then. With the seals would it be obvious if they need replacing or if I clean above as Nobby says I should be alright reusing them?

[Bibio]

if the pistons are teflon coated do not and i repeat do not take anything abrasive to them.

also while i'm at it don't clean anything with brake fluid, brake fluid attracts water which is bad and when it gets old it turns crystalline.

if the seal recesses are full of crap then as said use a dremmel with a nylon or brass disc brush and tiny minuscule bit of autosol. once clean rinse the whole lot out with brake cleaner and let dry.

do not be tempted to smother the seals in RRG. it's not the RRG that makes the pistons slide it's there to protect the seals as it stops them drying out and going brittle, it also helps crap from entering and getting underneath the seals. put some RRG between finger and thumb and rub the RRG into the seals then place a 'smear' on the outside (part that goes into the recesses) then insert. once the seals are in then rub some RRG onto the sliding faces of the pistons and don't get any on the top then slide the pistons in then wipe of excess RRG. if the pistons don't slide easily then you have twisted a seal so take out and check.

do not scrape the mating faces of the two calliper halves and if there is any crap on them then leave it as it was there so it wasn't causing a problem. cleaning these face might result in the callipers leaking. if they are really bad then you can use some fine grinding paste or autosol on a piece of glass and 'hone' them using a figure of 8.

[Bibio]

almost forgot. change the brake fluid once a year and while your at it strip the pistons out and give the callipers a once over and you will never have to buy seals again.

[dirtyred619]

Wow great loads of info to go at there, I'm almost looking forward to doing this, mainly as when I'm done I can safely ride the bike again.

Is there any difference to sorting out the rear caliper or basically follow whats been said, it's the stock rear just thought I'd get all the brakes in tip top condition all at the same time, new pads etc.

[dirtyred619]

Oh and brake cleaner, which one, is the Muc Off stuff any good, probably the easiest to get hold of.

[Bibio]

any cheep ass stuff you can get as they are all the same. try a car factors.

[dirtyred619]

Right I've taken the calipers off this morning but I was in a bit of a rush so only managed to get one set of pistons pushed far enough out to be able to get them out fully. Will I get away with using an electrical tyre pump to push the rest out or will I need to use a compressor? And will it push the pistons out fully or will I need to pull them out the rest of the way?

[Nobbylad]

Before I invested in a compressor, I used a bike foot pump and a length of rubber tube. Don't try pulling them out with pliers or owt or you'll score the surfaces. Sometimes a broom handle with a marigold or summat similar on the end well help you twist it out.

[dirtyred619]

Did you attach the tube to the bleed nipple or where the brake line goes?

[maviczap]

Right I've taken the calipers off this morning but I was in a bit of a rush so only managed to get one set of pistons pushed far enough out to be able to get them out fully. Will I get away with using an electrical tyre pump to push the rest out or will I need to use a compressor? And will it push the pistons out fully or will I need to pull them out the rest of the way?

My electric compressor pop's them all the way out with a nice pop!

A foot pump will still do the job, but with more control.

I took the bleed nipple out and used the little air bed adaptor in the bleed nipple orifice

[yorkie_chris]

If you get some proper stuck then 150psi won't move them, get in habit of using the hydraulics to do all work for you

[dirtyred619]

If you get some proper stuck then 150psi won't move them, get in habit of using the hydraulics to do all work for you

I will be doing next time.

Got the pistons out using a mini compressor normally used for inflating tyres it worked quite well, the only problem I found was trying to get them all out the same amount and equal but managed with a bit of fiddling.

So they're all cleaned up now and rebuilt ready to go back on be tomorrow, lets hope the problems solved and they work properly now. The back brake is fine but if I get time I'm going to do that aswell before finally being able to get back out for a spin.

[dirtyred619]

Well calipers are back on and working fine, no binding etc. Bled them off which took a bit longer than expected but got there and I've left the brake lever cable tied up to get rid of any last drops of air tomorrow.

So you'd think my job is finished and problems solved, well not quite. I managed to over torque 1 of the bolts fixing the calipers to the fork leg and it snapped (luckily just the bolt and not the caliper bolt hole)! So I need to get hold of bolt now to sort that out! Any ideas where best to try, I'm not sure on size either.

[Nobbylad]

Ebay or wemoto.com it'll be the same size as one of the other 3.

[dirtyred619]

Couldn't find those ones on wemoto and seen some on ebay for the right price but it's an auction that's still got over 3 days to run. Oh, and he wants nearly £5 for postage!! Gonna try a local bike garage first before I get desperate.

[Nobbylad]

Robinsons Foundry - £6

59145-33E00

[dirtyred619]

I've bitten the bullet and bought the ones off eBay, just hope they're the right ones but they'll be here tomorrow so if they're not I can get over to the garage and hopefully get one off them. It's a set of 4 so I'll have 3 spare at least then! Cheers though for finding the info above.