Bolt snapped in brake caliper mount.

[jdh72]

Recently when fitting a larger brake caliper adapter the bolt snapped when approx 2/3rds of the way in.

It wasnt cross threaded.

Tried drilling the bolt out, got most out.

Tried clearing threads with tap tool.

Tap tool snapped after less than 1 turn.

Ive now got a worse situation trying to remove the tap tool.

Its a mess.

I dont want to write the fork off, theres no suitable replacements available anyway.

Anyone know anyone who could help fix this please?

Cheers

JDH

 

[C R]

Recently when fitting a larger brake caliper adapter the bolt snapped when approx 2/3rds of the way in.

It wasnt cross threaded.

Tried drilling the bolt out, got most out.

Tried clearing threads with tap tool.

Tap tool snapped after less than 1 turn.

Ive now got a worse situation trying to remove the tap tool.

Its a mess.

I dont want to write the fork off, theres no suitable replacements available anyway.

Anyone know anyone who could help fix this please?

Cheers

JDH

The tap snapping is a bit strange if you were only chasing the threads. Was the tap the right one for the thread? There are some imperial threads that are very close to metric so look right, but will bind if you try to screw one into the other.

I think trying to drill out the tap is going to be your only option, but I very much doubt you would be able to do that by hand. Do you have access to any machine tools.

 

[Once a Wheeler]

The tap tool was only a single turn in, so it may not actually be very tightly engaged. Try supergluing the end of a thin metal rod or the end of a bolt which is too thin to engage the threads on to the broken end of the tap. When set, gently rotate the rod to see if it will disengage the broken tap before the glue bond breaks. Good luck.

 

[fossyant]

Drill a small hole (not deep) into the tap, then use an 'easy out' reverse threadded extractor - bloody work. Just removed a snapped bolt from son's engine block like this. A small hole (just a few mm deep) was enough for the tool to bite and undo the bolt.

 

[monkers]

Any chance of a photograph?

 

[C R]

Drill a small hole (not deep) into the tap, then use an 'easy out' reverse threadded extractor - bloody work. Just removed a snapped bolt from son's engine block like this. A small hole (just a few mm deep) was enough for the tool to bite and undo the bolt.

A tap is likely much harder than a bolt, though.

 

[faster]

A very tricky problem to solve, and may well be one of those situations where the best way to solve it would be to get a local engineering firm to do it.

Someone else has suggested drilling - no chance.

I've only ever seen one broken tap removed successfully with my own eyes, and that was done by just smashing it to smithereens with a hammer and punch. It didn't actually take too long - they are very brittle, but would your forks survive it?

 

[fossyant]

A tap is likely much harder than a bolt, though.

But the shaft material might not be (that's snapped) - only needs a small hole for the easy out to grab it and undo the thread !

 

[C R]

But the shaft material might not be (that's snapped) - only needs a small hole for the easy out to grab it and undo the thread !

They snap because they are hard and brittle.

 

[jdh72]

Tap was correct, M6 1.0 metric.

Im taking it to a local frame builder later this week, fingers crossed they can sort it.

Yeah its a nightmare.

Some pics of the saga attached.

That post mount looks a lot worse now with no paint left on it. Took it to a local vehicle brake specialist, they managed to get 3 metal prongs in the gaps and tried torquing it out after applying some heat, but was unsuccessful.

I thought about investing in a tap extractor tool but maybe best just leaving it to the framebuilders.

 

[jdh72]

Weve got a pillar drill, tried drilling it out but the bit just moves to the side on contact with the tap.

 

[keithmac]

When you say "got most of the bolt out" it looks like you have drilled it off centre so one side is soft aluminium and the other is still steel, that's why your tap has snapped imho.

Only way I've seen taps removed without leaving a mess is by using Spark Erosion but that's to save parts costing £1000's really.

Might end up having the post cut off and another one welded on.

Drilling a steel bolt out of a softer material is a skill, mainly you have to be dead centre or you can't make a satisfactory repair.

Only other option is to try and weld a nut to the remains of the tap and wind it out but that is a gamble as well.

 

[Gunk]

Drop the fork into a local engineering shop. They will drill it out with a pillar drill and put an insert in. Should cost you about £40

 

[silva]

The broken off tap part has a small contact surface - barely engaged.
Tap is hard, hard is brittle.
Maybe hammer punch it in the center, alot ticks, no big hammer blows, as attempt to create some cracks in the tap material.
Goal is to get a part of the tap material out, which would then provide room to hammer out the rest of the tap material from the circular edge towards the freed up center space.