Rear disc mot failure

[bwizz]

Just had an unusual "to me" mot failure the rear disc had microscopic cracks around a few of the cooling holes. I do brake hard on the back brake and these cracks are probably heat related.But still something i was not expecting. I have sourced a disc from the forum "thanks Andrew!
But trying to remove the disc the fun started.Before attempting to remove  I tapped all the relating bolts with a hammer but still the centre ripped out of two of the allen retainers. I then removed the allen heads with my angle grinder , this got the disc of the hub, but left me with the remains of the stuck bolts to remove. despite heating the alloy hub with a blow lamp , they are still stuck , not much for the mole gripps to hold now!
drilling them out is going to be difficult as they are very hard. oh well i'll see what tomorrow brings ,might try and find somebody with a oxy torch
to get more heat on it

[chaz]

what about welding a nut to it? the heat may do the trick? a mig welder might be best.

[bwizz]

Hi ta , i don't have a mig myself , or gass , I don't think the access is good enough to weld to ! so I will have to take it to someone as i'm stuck !

[slimwilly]

You may want to be careful of heating the alloy hub,(if it is) this may make the alloy soft.

[bwizz]

Not many choices really to save the wheel. drilling and tapping is going to be very difficult as the remaining studds are really hard

[bigsteve]

I Know this is a bit like shutting the door after the horse has bolted but
 
  I had to remove allen bolts from my exhaust manifold on my Suzuki and all the centers had rusted and rounded out when I tried to remove them
 The answer was given to me by a garage I deliver to and was a set tool  I have never seen before
 
  They lent me a set of  Irwin Bolt-grip nut removers
 
 Easyest way to explain it is they are external easy outs they go over the outside of bolt and as you go to undo bolt the socket bites on to the outside of bolt and in my case undid all 8 rusted bolts
 
Sorry this is a bit late for you but may help others
 
 

[bwizz]

Hi never heard of them either .in my case without heat nothing will shift the remaining studds.  I had a allen head tool with a half inch ratchet when the innards ripped out
so to say the least they are very tight, I have a feeling that the bolts were put in with thread lock , as they are still megga tight even without the disc in situ, options i think are either a special  hardened drill bit to drill and tap. or lots more heat, with the risk that the casting collapses

[His Dudeness]

Your local welder should be able to get them out by welding a nut on or check out deadeye's post here http://foc-u.co.uk/index.php/topic,6658.0.html

[slimwilly]

Engineering shop and drill them out, normal bit,slow spinning,power feed,

[Dead Eye]

Unfortunately mine were exhaust studs, not the rear disc but having said that I do have a similar issue. My rear disc is stuck fast but isn't quite at the end of its life yet...

[GrahamB]

Bit late for what I'm about to say in this case but I swear by this method if the bolt heads start to chew up. I hammer a multi spline bit in the slightly damaged bolt head where an alan key fitting should go. Forget the size but if it grips nicely but won't push in then that's the one! Relevant socket & use a breaker bar. Have to tap the bit left & right after to get it out the bolt head after but much better than all the hassle you are having now!
 I would have to say mig weld a nut on the stud now as a first attempt.

[alan sherman]

I bought a new wheel off ebay. Cheapest, easiest solution.

[Pat]

I Know this is a bit like shutting the door after the horse has bolted but
 
  I had to remove allen bolts from my exhaust manifold on my Suzuki and all the centers had rusted and rounded out when I tried to remove them
 The answer was given to me by a garage I deliver to and was a set tool  I have never seen before
 
  They lent me a set of  Irwin Bolt-grip nut removers
 
 Easyest way to explain it is they are external easy outs they go over the outside of bolt and as you go to undo bolt the socket bites on to the outside of bolt and in my case undid all 8 rusted bolts
 
Sorry this is a bit late for you but may help others

I had a set of these to hand when I needed to dismantle a couple of GPZ900s that had been stood in a damp lock-up for years, I had to tackle a a number of rounded rusty cheese bolts & these worked on every one of them, brilliant bit of kit!

[ghostbiker]

Something I do on bolts is as soon as they start to round I swap to a star bit and hammer it in. About half the time it will give enough grip to get it out. But need to do it as soon as it starts to strip. Go to far and nothing left to grip to.

Like the sound of the above tool though, tried all sorts of gadgets over the years and most never work.

[Dead Eye]

I bought a new wheel off ebay. Cheapest, easiest solution.

After looking at the prices this is something I will end up doing - I'll give the bolts a go myself when I'm prepared to have the bike off the road but with the knowledge before hand that I will more than likely need a new rear wheel.

[bwizz]

With hindsight, i would have put the allen bit on the end of my impact screwdriver
as I think its the same size,

[bwizz]

sorted ! I took the wheel to a local garage "with a competent welder"
 
He welded nuts on the remaining studds ,but the heat from the weld was still not enough to looses the studds , After 3 attempts and the hub being heated with a gas axe the 2 studs finally came out. huge sigh of releif on my part, there would not have been a hope in hell with a  home blowlamp
the nice man charged me a tenner, so with £25 for the disc and £10 for the gas not to bad ,but got to find 2 retaining bolts yet.
I,ll put the bolts back with some gold high temp lube,
and hopefully never  touch it again, I suppose the bearing could be cooked though!
moral of the story, Allow plenty of time for developments if working on the disc rotors