Brake pads disappeared after about 200 miles

[Craig321]

Recently got some Goldfren S33 sintered and after about 200 miles they're gone, so much so that I was down to the metal on the way home today and more than likely ruined my rear disc - it's really rough now, not sure I'd want to run a new set of pads on there.

The goldfrens were from a reputable seller on eBay, cost about £15 which is the going rate, so don't think they were fakes, but you never can be sure I guess.

Any ideas what might have caused this? Bad fitting on my part? Is there anything I should be doing i.e bleeding the rear brake or having it looked at professionally?

Gutted as now this is going to cost me at least £80, discs aren't cheap

Also can anyone recommend some sintered pads and a new rear disc for a Honda Hornet F4 please? Don't really want to go Goldfren after this, even if it was my fault or something else that caused it.

Thanks.

 

[Craig321]

There is no way genuine brake pads are going to disintegrate after only 200 miles, not unless your riding around with your brake jammed on, which ide hope you would've noticed.

Nope, nothing unusual when riding. Normal slight brake hissing noise when wheeling it about which has always been there on this bike (and most other bikes in my experience). Would have definitely noticed it when wheeling it about if it had been jammed on enough to cause this sort of wear, and of course when riding.

The bike has actually been better than ever in terms of power and smoothness since changing the chain and sprockets, so definitely not been riding around with them stuck on!

That's just scarey, I'd investigate the source & report them before somebody gets ****** up.
I'd strip the rear caliper down as well just to be sure.

What does stripping them involve? Anything difficult, or anything that needs special tools? It's not something I've done before.

I will be looking into them on eBay. They were one of these sellers with 10s of thousands of feedback and 99%+ so thought I would have been safe!

 

[Craig321]

were they from m&p ???

ive been using goldfren now for about 6 or 7 years,on both my bikes and ive never had them wear out that fast

the ones in my zx6r atm are over a year old and I ride everyday/year round

ive always bought mine off m&p, nobody else

if you can find a cheap engineering firm you could get your rear disc skimmed,to take all the grooves out

They weren't unfortunately, they were from an eBay seller with 100,000+ feedback so thought they would be ok.

as said they cant be legit pads
is the pad is still on the backing plate
had it warn away or the pad broke off the metal backing?

Completely worn away on both sides, no pads left at all. No sign of them braking off.

Possibly either stuck piston or stuck sliders, though on many bikes you take the rear calliper off the sliders to replace the brake pads so you would have noticed this.

When you put the new pads in, did you pull back the dust cover and clean the piston thoroughly before pushing the piston back in? If there is a heavy build up of corrosion on the outside (due to a holed/leaking dust seal) then pushing the piston back without doing this can cause them to partially seize.

I thoroughly cleaned around the piston and that area, then pushed them back in. Surely if they were sticking I would have noticed and they also would have felt terrible? They felt good up until the point when they weren't there anymore!

to tell if your rear brake is sticking on,ride around for few minutes then touch the disc,it should be very slightly warm but if its hot to touch then the pads are dragging (its normal for them to ever so slightly drag on the disc but not excessively so)

(if its really bad you'll feel it slowing you while riding around)

Yup, that's the first thing I checked after the first ride with them, disc was slightly warm as you describe and everything felt good. If they were dragging excessively I definitely would have heard when wheeling it about as well.

 

[Craig321]

how badly scored is the disc? if its mild then new pads will wear it off

if I were you id try another pair but from m&p this time and see how long they last,they are verygood pads imo,i wouldn't suggest them otherwise

chances are they were fake ones or they wouldn't have worn so fast,

I rate them as long lasting/as good stopping power as the ebc sintered pads

EDIT: ill grab a pic of my rear pads when I get chance 2morro,you'll see how much meat is left on them,put them in just before mot time which was around march I think

It's pretty bad, fingernail catching type stuff. I'll get a pic tomorrow but it doesn't look great.

 

[Craig321]

Unless they were completely seized they wouldn't have felt much different, you don't get a lot of feedback from the rear brake anyway.

Did the pads move freely within the calipers? Poorly machined pads or a build up of corrosion within the caliper body can cause the pads to bind even if the piston is free.

The other thing that can cause binding brakes is if the master cylinder isn't returning fluid back into the reservoir, due to i.e. corrosion within the MC, partly seized rear brake pedal pivot or linkage, something bent.

Also, sounds stupid, but you haven't just started using a new pair of boots have you?

Thanks, will check out all that just to make sure before putting the new pads and disc on.

Nope, no new boots. Only changed the rear brake pad as my previous organics were down to their limit after about 2 years.

I think I'll take the calliper apart today and try figure out what's going on, if anything. Don't want to spend £80+ just to have the same problem! I guess I'd need to bleed the brakes etc as well?

Thanks.

 

[Craig321]

Callipers are off, piston is out and busy cleaning now.

Is there anything else I should be replacing while the thing is off and the piston is out? Washers maybe? http://www.ebay.co.uk/itm/Honda-CB-...pt=UK_Motorcycle_Parts_13&hash=item5aefc56af8

Not too sure where new washers like that would go as the caliper can't really come apart anymore.

 

[Craig321]

Cheers. I guess I'm just a bit worried about how deep the grooves are now on mine compared to yours for example. I guess new pads will wear that layer off quite quickly though.

 

[Craig321]

That disc has well had it and looking at the wear yes the brake has been stuck on, the inner bit looks like stuck pad material, I bet if you put a wire brush to it most of that would come off, but it looks like there is a big lip at the top, and its not consistent all the way around so maybe warped also? if you spin the wheel whilst looking from behind at the disc you should be able to see if its warped.
Rear discs are cheap for most bikes so shouldn't cost too much to sort out.
Does the piston move easily now it has been cleaned?

Sticking rear calipers are a hilariously common problem on so many bikes simply because they don't get used that much, as someone else said the feel is rubbish and on many bikes the design is horrible, upside down so all the crud just sticks inside the caliper!

I've not put the piston etc. back in yet as I only took it off on Sunday afternoon to clean and it's dark when I get back from work so haven't had the chance to bleed etc. yet... will sort it all this weekend when I have the disc and pads.

omg thats is well shot, you should have known / heard / felt thats something was wrong. i have seen it where the brake compound just falls off.

I still cant believe you didn't feel anything, it must have been binding

I know! It's weird. I mean, yeah of course I noticed when the pad was pretty much gone, but no indications before that. The bike has been running better than ever since I replaced the chain and sprockets and the rear brake was way better than the old organic I had on there.

I also checked every time I got off the bike for a few days after putting the new pad on and it was perfect. I guess it could have started binding on Friday/Saturday when I did a good few hours riding. No noises or anything though.

Anyway, decided to go for a new disc and matching pads - both EBC, recommended ones from m&p. Also had EBC previously on the pad and it lasted 2 years.

 

[Craig321]

Went for the EBC Prolite disc, EBC sintered pads to match and also thoroughly cleaned the caliper and replaced the seal washers just so I'm covered on all areas. Also fully re-bled of course.

Went for a ride into town today, did some slow stuff, so a fair bit of back brake work. Also did some country roads, stopped after a while at the side just using my front brake so I could check the temp of the back ones without any use (i.e. to see if they're sticking) and they were cool, so no problems there.

Very pleased all sorted now.

Oh and the vacuum bleed kit I got about a year ago and have used twice now was a total waste of money. I was bleeding with it and not getting anywhere - it wasn't sucking anything. Ended up just sticking a pipe on the bleed nipple and open, hold brake in, close, etc. and got it bled perfectly in a few mins! I just used the pipe that came with the bleed kit which is stiff stuff so was a bit awkward and didn't grip onto the bleed nipple very nicely. Definitely going to invest in a length of nice bendy hose. You don't need any more than that.

 

[Craig321]

a length of standard tropical fish tank air pipe is all I use,and a jam jar

nice tight fit over the nipple

Yep, that's what I'm going to pick up, hopefully from the hardware store tomorrow as my fronts need some fresh fluid anyway. The pipe I have is awkwardly loose on the nipple and isn't very flexible, so it'll pop off or leave a gap if it's not perfectly placed, managed to get the rear done properly though.

All the stuff I read when I first bled my front brakes said the suction kit thing makes bleeding so much easier, so I bought a MityVac kit. It really doesn't help and was a waste of money! Simple tube and jar on the end is all you need!

 

[Craig321]

If you use a vacuum bleeder than you need to generously cover the threads on the bleed nipple in either silicone grease or red brake grease, otherwise it just pulls air in through the threads.

S'pose so! Still though, there are about 4 points of potential air leaks. The problem was likely due to it not being sealed properly as you say, but when I can just stick a hose on, other end into a bit of clean brake oil and use the pedal to push liquid through, I'll do that every time. Cheap, no hassle and much quicker.

It's a big shame, the mityvac wasn't particularly cheap, something like £40 which I thought would be a decent investment for future bleeds and bikes, but turns out it wasn't.

I guess it may come in useful if I ever get a bike with ABS. I hear you need a pump to bleed those?

Brakes are awesome now and getting better every use. I can finally get round to changing my front tyre next weekend now that the brakes are sorted!