Brake rub...I think

[warrenpfo]

I had not noticed it prior to fitting new rear discs but when taking a left hand corner there is a noise that comes from the right hand rear (outside) wheel which sounds a lot like a pad rubbing on a disc. I plan on rebuilding the right hand rear brake calliper this weekend if I get the chance as the left was sticking and so bout a full kit to replace the rubbers etc.

I can only think that under the stress of taking the corner something has enough movement in it to create the rubbing noise. It is possible that the rear disk is “loose” enough for it to then touch the pads under the sideways force of taking a corner or would you put money on the fact is has something to do with the calliper?

I cant seem to work it out but just thought I would ask.

 

[adrianr]

Interesting. I replaced my rear discs on my 80 last weekend and on cornering i can now also hear something gently rubbing that was not rubbing before.

I think it might be the guard behind the disc but not sure why it would start rubbing now on cornering.

Look forward to others input!

 

[frank rabbets]

I don't think you would hear a pad on a disc. The brakes don't make much of a noise when you press tha brake pedal. My rears were stuck on slighly on my 80 but were silent. Could it be the rear shoe coming up against a wear shoulder especially if you have adjusted them up.


Frank

 

[adrianr]

Thanks Frank, I'll have a dive in their again.

i spent a long time getting handbrake set up right. When i replaced the discs i the handbrake shoes look like they had plenty of meat left on them.

I wonder are the 100's a similar set up?

 

[frank rabbets]

My 100 looks the same so 99% chance the same. I know when I was adjusting my shoes they did make a noise when adjusted up and the hub turned by hand but I cannot hear them on the road. See if the drum gets hot after use but try not to use the foot brake too much as the pads will heat the whole thing up.

Frank

 

[adrianr]

Thanks Frank - Warren - sorry for the hijack!

When first adjusted the handbrake was a bit too tight and the drum part did get quite warm. i then spent enough time to set it up right and now it does not rub.

Best thing I think it to get back inside and have a look see.

 

[Jon Wildsmith]

check the little stainless clips that the pads sit in have a gap to the disk, they can make a rubbing noise like that if too close to the disk. Cable adjustment is at the back axle on a 100 rather than at the lever on an 80 but adjusting the shoes is the same.

 

[adrianr]

Thanks Jon

I'll check that later today.

 

[adrianr]

Thank you again Jon you were spot on in my case!

Was those clips plus for some reason I has put the wear indicators on the bottom of the pads All quiet now

 

[Jon Wildsmith]

Glad you got it sorted Adrian

 

[warrenpfo]

Right I seem to have found the problem I think.

The caliper certainly needed some attention as it was bone dry and a real bugger to get the piston out so glad I decided to overhaul it.
With the caliper removed I whipped the disc off to notice 2 little scratch marks that had developed on the thin backing plate. I can only assume that the combination of the new disc and maybe the backing plate having been pushed in was making it rub.

I gently massaged the backing plate out a little and then put it back all together. It now really required some force around a sharp corner to get any rub so maybe it needs just a little more massaging to get it right.

I just wanted to check that nothing else was at play here. I jacked up the wheel and did the whole 12 and 6 and 3 and 9 shake with no movement but wondered if there could be anything else that I need to check as its not usual for the backing plate to rub unless it has been bumped in with some force which I cant seem to see having happened but you never know.

 

[Jon Wildsmith]

You can't really check the rear wheel bearings on a 100 by wobbling the wheel as the drive shaft stops it wobbling with the kind of force you can apply even if the bearing is bad, you'd have to fetch the whole hub / shaft assembly off to check it and even then it will have to be pretty far gone to tell

 

[warrenpfo]

Thanks I think ill just gently push the backing plate out just a little bit more and see how we go.