Removing this broken bolt

[zain611]

Hey everyone, 

So bought a rear ST 150 beam and was removing the parts I need to do a rear drum to discs brake conversion however when undoing the bolts which hold on the hub one of them broke. At the moment I sprayed some fluid and left that to soak in. My dad has an idea on what to do but thought I might ask for others opinions on how they'd tackle this.

[dezwez]

pair of mole grips

[Turvey]

Place a nut on top of the broken bolt and fill the void with weld. The heat caused by the welding will help free it and you can use a spanner on the nut to unscrew it. 

[Jonro2009]

Penetrating fluid will need a good few days I would have thought. Use a punch and mark the centre of the bolt, then use a left hand-drill bit to drill into the bolt. At some point hopefully the bit will be in the right position for the drills torque to start to turn the bolt in the opposite direction and start to remove it. Remember to clean the thread when your done, any metal filings will need to be removed or else they may jam the new bolt going back in.


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[TomsFocus]

Depends what tools you have access to.  Welding a nut on top would be best if you have access to a welder.  I've got some bolt removers that I'd try if mole grips failed.  I reckon that'll be a hard bolt so drilling it out may take a while.

[stef123]

Without doubt get some heat on the area and a pair of mole grips that’ll come out easily. 

[zain611]

Thanks for the feedback. So applied heat over it with a blow torch and began to turn it using mole grips. Half the top of the bolt snapped off sadly. I think this is welded on with rust. May go with @Jonro2009 and @TomsFocus strategy on drilling through it. Will use a small drill bit and drill through it slightly increasing the size of the drill bit until it gets close to the thread. My dad has this part which goes arround the thread and removes any materials between the thread. Will update tomorrow.

@Jonro2009 I think I've given you your 1000th like 

[zain611]

Here's a picture of what's happened 

[Russ]

Drilling it outs your best bet. As you say start with a small drill progressing to bigger diameters. You ‘may’ need to run a tap down the hole to remove the last remnants of the old bolt. 👍🏼

[Jonro2009]

You have, cheers Zain! 

You probably should have left it another few days for the penetrating fluid to work, previously I’ve left a bolt for the best part of a week. I wouldn’t like to keep stepping up the sizes of drill bits as you are likely to find that you damage the thread in places and then running a tap down it will most likely cause it to be a slightly looser fit than it should be. If you are going to do it that way then use a ‘chaser’ instead as it shouldn’t damage the existing thread but it will remove bits of the old bolt left attached to the thread. I’d still recommend a dedicated left hand drill bit with a fluted tip to grip onto the bolt.  Has your dad got an ‘easy-out’ tool and ‘Heli Coil’ 

[zain611]

14 hours ago, Russ said:

Drilling it outs your best bet. As you say start with a small drill progressing to bigger diameters. You ‘may’ need to run a tap down the hole to remove the last remnants of the old bolt. 👍🏼

 

12 hours ago, Jonro2009 said:

You have, cheers Zain! 

You probably should have left it another few days for the penetrating fluid to work, previously I’ve left a bolt for the best part of a week. I wouldn’t like to keep stepping up the sizes of drill bits as you are likely to find that you damage the thread in places and then running a tap down it will most likely cause it to be a slightly looser fit than it should be. If you are going to do it that way then use a ‘chaser’ instead as it shouldn’t damage the existing thread but it will remove bits of the old bolt left attached to the thread. I’d still recommend a dedicated left hand drill bit with a fluted tip to grip onto the bolt.  Has your dad got an ‘easy-out’ tool and ‘Heli Coil’ 

I'm going to ask my dad to be certain what he's going to do. Was looking at this video and the guy showed 2 methods using a drill past the half way segment. This bolt looks rusted shut and the rust may have gone into the bolt which may be why it broke easily. 

 

[zain611]

Just to update my dad drilled a hole straight through it and has ordered a left hand drill bit. Hopefully the threads will be clear of the remaining remnants of the bolt

[zain611]

Bolt is now removed. 😀😀

[Jonro2009]

Top news!  Crack on with the conversion now

[zain611]

Here's pictures of the results