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Discussion Starter #1
Hi All,

So i recently started getting a a large scraping sound coming from the passenger side wheel area. Upon further investigation i found that the disk was rubbing against the pads. So i replace the disks and the pads thinking that i have buckled rotor. However, i still having an issue with the disk rubbing against the pad. I thought that the wheel bearing may have gone bad. But there is no play at all in the wheel and when caliper is off the rotor turns freely with no noise at all. Any suggestions on what could be the issue?

Many Thanks,
 

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Sticky caliper or slider. More common on the rears but all these cars are old now and the pistons are pitted and the sliders corroded. Did you notice one pad was significantly more worn than the other.
A reconditioned caliper could be a good move and I found new hoses also improved the solidity of the petal.

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Also the mud shield on the rears will have corroded and can rub on the disks. This can be replaced or just binned. I find an infrared thermometer aimed at each wheel can give useful data regarding the operation of the brakes rather than solely relying on your hearing.

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Discussion Starter #4
Hi dgmayhead,

Thanks for the response. I don't think it is the piston and I've checked the clearance of the mudsheild and no interference there. It appears that the disk isn't square to the pads, and that the flange holding it is slightly off as the rotation of the disk is not constantly, with resistance presenting in certain parts . Can i assume that there is a problem with the bearing? could an over torqued hub nut cause this? Caliper appears to be in good order. Although i am no expert so could be completely off on this.

Thnanks
 

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Did you scrub the hub surfaces clean before putting the new discs on? I assume it's the rears you are describing. If so the rubber protecting the piston tends to fail as the hand brake puts a rotation on the piston and the rubber gator can't really cope with this for the life of the car. The rears do little braking effort and last for years and so it's pretty unsurprising that by the time they need to be wound back in for new pads they have deteriorated. I'd be fairly confident that the rear calipers aren't going to be in good shape on any car this old. I put new calipers on my 156 eventually after much arsing about convincing myself there was a cheaper solution.
If you still think your hub surfaces may be the issue why not measure the run out by rotating the wheels against a fixed point or dial gauge. I can't see how the hub can become wonky without other more serious symptoms.



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I think careless hammering or similar may have distorted the pad carrier. This would explain pads not being straight to the disc and the rubbing noise.
It would also explain the lack of wonkiness (run-out) in the disc.

Fix it with a hammer.:blabla:
 

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Discussion Starter #8
Thanks All,

Had another check today of all the wheels just to make sure that the area in question was right. I disassembled the front passenger brake and disk and re-assembled again sound is much better but still slightly there. may take your hammer the disk carrier approach fruity and see if this solves the issue for good!
 

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I may have been wrong with my suggestion. You took it apart again and did not notice anything amiss (you would have said so if you did).

My suggestion would be best checked by removing brake pads and checking the clearances between the carrier and disc faces (both inner and outer at top and bottom positions).

If the splash shield is in its correct position and not fouling the disc then that can be discounted.

The only other thing springing to mind may be crud which is formed from brake dust. Very occasionally, this can build up and touch the outer disc (at it's maximum diameter) where the carrier bridges across the disc for the part of it which holds the outer pad. A blunt scraper and/or a thin but stiff caliper brush should be used to clean any solid crud build up.
Check this with pads out, BTW (at same time as checking carrier to disc face clearance).

Whilst at it check the inside of the caliper housing bridge, again for a build up of crud. Just give everything a good clean and look very carefully for any signs for running contact.
 

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Discussion Starter #11
Hey All,

Managed to solve this. I disassembled the brakes cleaned all surfaces with a wire brush as to ensure that all dust on the caliper and backplate was removed. I then removed the hub nut ( it was definitely over torqued as it took a lot of wd 40 and me standing on the end of a half meter long breaker bar to loosen it). Re torqued the nut to manufacturers specs and bleed the brakes. no noise now, all running sweet.

Thanks for all your help.
 
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