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      06-19-2012, 06:52 AM   #1
Subzero2003
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Rust band around outside of rear brake disc

HI all,

Was just wondering if anyone had ever had this happen to them? Pads were changed about 6 months ago and i've only really just noticed that it looks as though one of the pads is only making contact with half of the disc? :

Offending side:



Other side:


thanks!
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      06-19-2012, 07:10 AM   #2
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There's a bit of grit in the sliding mechanism. Strip it down and clean it. You'll just need to remove the caliper from the strut (17mm socket) and then remove the slide bolts with a 7mm allen key. Clean the slide bolts with a wire brush, blow crud out from piston and surrounding area with compressed air, add some coppaslip - done. Half-an-hour's work.
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      06-19-2012, 09:49 AM   #3
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Hey Sub. Yeah what xenon said. If you're up for it, the 2 bolts are in the back of the caliper. Real easy job. Looking at 10 mins max to take the assembly apart. Best way to eliminate any trapped grit affecting the set up. It is however more than likely you may need a new pads. After you rectify the problem.

If you're not willing to get your hands dirty.... On sunday after work after months of clicking noise coming fromt he front left. I took the car into kwik fit, to check all the bushes and brake assembly. They found no faults with bushes or control arms, and concluded that the clicking was coming from the front left. The chap took the brake assembly apart, swapped over the tension clip and greased the side hooks of both pads and tightened everything up. Long story I know.

But point being. He didnt charge me a penny. Noise gone, I slipped him a cheeky tenner.

Good luck bud.

Last edited by A_P; 06-19-2012 at 10:29 AM.
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      06-19-2012, 09:51 AM   #4
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also, How thick is the lip from the rust section on the disc?
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      06-19-2012, 10:22 AM   #5
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You can see that whoever fitted the pads was not exactly liberal with the coppaslip. You'll perhaps need to skim / replace the disc too or just put up with some noise for a bit.
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      06-19-2012, 04:24 PM   #6
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Cheers for the replies guys. The lip between the shiny bit and rusty bit is non existant as far as I can feel. Had a good fiddle around with the calipers and pads and they seemed to be sliding easily enough. Didn't have a 7mm Allen key though (typically I had every single size apart from 7mm). Taking it to a garage on sat to have front pads fitted and them to look at the rear pads. Can't be bothered to roll around on the floor atm - too busy!
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      06-19-2012, 06:17 PM   #7
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Sorry in a rush but it looks like the slider for the caliper may be seized or just not working properly due to needing a good wire brushing/copper slipped.

the rust on the disc even once caliper carrier/slider is sorted may not go away so it'll either need skimmed on a milling machine or if you're not all that fussed a flap disc on a grinder will take the worst of the rust off and the pad may recover and eventually take off the rest (good chance it won't though) or alternatively renew the discs, but the pad may now be worn un-evenly so may need discs and pads.

HTH and i've maybe repeated what someone else has said, my bad if so!
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      06-19-2012, 06:21 PM   #8
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+1 with everyone else, but also add a type of grease to that part.

You will see the surface that the pad slides on. wire brush down to the metal and then apply grease.

NOTE: NOT NOT NOT on the pads OR the rotors!!!!!! I'm talking about the Brake Caliper Mount here. You'll see the part the pad rests on if you take off the Caliper.

Last edited by DUI Elite; 06-20-2012 at 08:39 AM.
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      06-20-2012, 03:12 AM   #9
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look at the surface condition of the untouched disc portion, its horrendous, looks like the pennines!

are you sure it was ok recently?
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      06-20-2012, 05:14 AM   #10
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OP, did you not "feel" anything weird while braking? was the braking performance not affected? if only part of the pad was in contact with the disc.
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      06-20-2012, 07:30 AM   #11
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Quote:
Originally Posted by zltm089 View Post
OP, did you not "feel" anything weird while braking? was the braking performance not affected? if only part of the pad was in contact with the disc.
I think it is a rear disc. In which case may be more difficult to notice.
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      06-20-2012, 12:07 PM   #12
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Replace the discs and ensure everything is sliding etc.
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      06-20-2012, 12:18 PM   #13
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Quote:
Originally Posted by Dr Dave View Post
Replace the discs and ensure everything is sliding etc.
Sort of agree with this. But your pad has probably worn unevenly, so new pads wouldnt hurt

But make sure you clean down that part that the pads rest / slide on (on the caliper mount), or this will happen to the new rotors and pads too.
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      06-27-2012, 06:26 AM   #14
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Hi all,

Sorry i haven't updated this thread, but thanks to everyone who have replied. I took the rear caliper off the other day and had a good play around with everything. The sliders "seemed" alright, but they weren't sliding massively smoothly and they had a couple of uneven bits on them. I scrubbed them hard with a cloth to get them clean and shiny again, applied copper grease to them and put some copper grease in the hole and made sure they were sliding cleanly.

The pad seemed ok, although to the eye you could see the difference between the part that had been making good contact, and the part that hadn't - the part that hadn't was a slightly different shade of colour. There didn't appear to be any lip on the pad. Anyway, i refit everything and the brakes seem as good as ever, so i'm just going to see if the rust wears down now that everything has been reseated, i hope it does, if not - i guess it'll be new pad and disc time!
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      06-27-2012, 06:29 AM   #15
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Double post!

Last edited by Subzero2003; 06-27-2012 at 06:45 AM. Reason: Double post!
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      06-27-2012, 07:48 AM   #16
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Copper slip apparently reacts with the rubber that the sliders slide in, it makes the rubber swell and the sliders can apparently not slide as freely. http://forums.sv650.org/archive/index.php/t-163505.html

Having said that, most garages use copper grease and most cars seem to be fine, so I wouldn't worry about it. Just letting you know really.
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      06-27-2012, 09:06 AM   #17
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...

FFS. Was pretty liberal with it on that rear caliper.

Oh well, it'll be ok hopefully. Thanks for the info though.
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      06-28-2012, 01:16 AM   #18
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Yeah should be fine - all my cars I notice a prev owner/mechanic has used copper slip. I just wipe it off and use my lithium grease. None of them have suffered for it.

Just thought I'd point it in case you develop a problem with sticky calipers, you'll remember this thread.
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