Bolt stuck - any suggestions ?

Gecko · Apr 5, 2003

I have just been fitting my set of Vern's lovely stainless bolts and everything was going just great until the very last one.(Sod's law....) Whilst fitting the brake caliper replacement stainless steel bolts the allen key slipped and stripped the inside of the allen bolt head and now I can't get one last bolt out to replace it with the new stainless one.
On the brake caliper there are 4 bolts in line on the top of the caliper two outer ones sit proud of the caliper and the other two are counter sunk. It's one of the counter sunk ones that the allen key stripped.
I have tried using a slightly larger Imeprial measurement allen key but it is slipping too.
Anyone have any ideas how I can maybe get this out. I don't want to start drilling because of the risk to the brake caliper but are there any tricks of the trade I could use to get this little sod loose ?
Cheers
Gecko

Jon · Apr 5, 2003

Superglue/Araldite the allen key in the stripped bolt? :confused:

you won't be keeping it and allen keys aren't that expensive.

Phil Reynolds · Apr 5, 2003

Years ago when I used to be a car mechanic, when a bolt had rounded off, one of the tricks was to get a centre punch and place it on the outer edge (as you could on an allen bolt face) and make a punch mark on the edge. With your hammer & punch, angle the punch downwards and hit it with your hammer in an upwards-anti clockwise motion. It worked every time.

Good luck

Phil

Panzer Patrol · Apr 5, 2003

If you take the caliper off, pull the pad pin and remove the pads. Turn it over and have a look inside. If you are lucky, the one you are after may be visible. (I know some are, but not sure which one you are after) Grab it with a set of mole grips and heave.

Check out a set of English size allen keys, there may be one which is slightly larger than the metric one. Belt it in with a hammer to make it fit. After that I'm stumped. Best of luck :confused:

Panzer Patrol · Apr 5, 2003

RE: Imperial allen key...you've tried that...Sorry Gecko, should have read your message more closely.

Deadskin · Apr 5, 2003

Hi G
You need one of these babies

(stud extractor)
Could you post a pic of the caliper please (just a little one)

G

nobby · Apr 5, 2003

bolt struck

hi
get a torx bit its like an allen key but lookes like a star hammer in to the bolt then undo easy
nobby the courier

Greg Masters · Apr 5, 2003

Without a photo, it's a bit difficult to picture your problem, but if this is a caliper mounting bolt, you will have to be able to apply a fair bit of force. For that reason, I'd avoid superglue and araldite, neither are strong enough for this sort of problem.

The stud extractor I would save as last resort - they are a one-way ticket - if you start with them and it doesn't work, you're in really deep sh*t!

I'd start by getting the tightest fitting Allen-head socket you can find. If necessary, hammer it in. Then use an impact driver, making sure that it will turn in the 'undo' direction. Hold it square to the bolt (that was probably your initial problem) and apply gentle undo twist by hand. Then give it one good heavy belt with a substantial hammer (1 kg min). If that doesn't work, take the Allen socket and the bike to an expert MIG or TIG welder and have them weld the Allen socket to the bolt head. If that doesn't allow you to undo the bolt, try the stud extractor!

:hammer

Greg

Gecko · Apr 5, 2003

gauloises said:
Hi G
You need one of these babies (stud extractor)
Could you post a pic of the caliper please (just a little one)

G

Hi G,
Unfortunately I don't have a digi camera at the moment. I am stuck with the R/H front calaiper. Here is a screen shot from the workshop manual . What this picture doesn't make clear is the fact that the bolt , when screwed in , if flush with the caliper . This means there's nothing to grab onto and if the others are anything to go on, it needs a fair bit of force to make it move.
All suggestions welcome.
If the worse comes to the worse I'll just leave it in. It's in place, not doing any harm so rather than risking anything I'll just have one none stainless bolt ......but I'm not ready to be beaten yet

Steve · Apr 5, 2003

I've got a similar problem. Got to the very last of Verns bolts, and I can't undo the old one. It's the lower of the four caliper bolts, and it feels like it's gonna shear off. I'm just feeding it a bit of Plus Gas every day and hoping it'll come loose in the end.

Greg Masters · Apr 5, 2003

Gecko

OK now I've seen which bolt you are referring to.

Two questions come to mind.

Why are you changing the bolt?
Why not leave the one you have got in the caliper?
[/list=1]

Greg

Gecko · Apr 5, 2003

Greg Masters said:
Gecko

OK now I've seen which bolt you are referring to.

Two questions come to mind.

Why are you changing the bolt?

Why not leave the one you have got in the caliper?
[/list=1]

Greg

Greg
No reason other than pure vanity. All the others are stainless , nice n'clean n'shiney ....except this one.

boxer · Apr 5, 2003

Greg's right.

leave it alone.

You've done a bad, bad thing. Could be the bolt is loctited in. It might be best to just forget it. From the looks of it you've going to have to resort to drilling holes in your bike or start hitting it.

This is from the BMW PDF.

Gecko · Apr 5, 2003

scurrell said:
I've got a similar problem. Got to the very last of Verns bolts, and I can't undo the old one. It's the lower of the four caliper bolts, and it feels like it's gonna shear off. I'm just feeding it a bit of Plus Gas every day and hoping it'll come loose in the end.

Scurrell - isn't it a real pisser ! I guess in my enthusiasm to step back and view my handy work (courtesy of Vern) I overdid it on the last one and the damn allen key just slipped.....now I'm paying the price. The rest look great so somehow I'll get it shifted.
Someone mentioned the idea of aralditing the allen key in - this got me thinking - not araldite but maybe spot welding the allen key would enable me to get it turning.....all I need is a welder. I'll see if there are any less drastic ideas first.

Greg Masters · Apr 5, 2003

Gecko said:
No reason other than pure vanity.

"like as it were a moth fretting a garment : so every man is vanity"

:angel

Far too profound for a Saturday night!

Greg

Greg Masters · Apr 5, 2003

Gecko said:
all I need is a welder

I think you might have missed my posting on this above!

It's critical that you don't distort the caliper. You need a high temperature, low heat weld.

Greg

THE PICT · Apr 5, 2003

Try Gregs idea exept I would hammer a torx head into it as that will give more grip than a bigger allen bit.Then use the impact driver and a hammer.

Rampant Stallion · Apr 5, 2003

I'm not sure I understand that bit above about a high temperature, low heat weld :confused:

Why not try a blob of valve grinding paste on the end of a tight fitting Allen key? It helps fill the gaps twixt bolt and key.....
The Torx bit and impact driver idea is o.k. but don't wack it so hard that you break the alluminium caliper mount!
A bit of heat usually helps loosen siezed steel bolts in alluminium.

Deadskin · Apr 5, 2003

Caliper bolts

boxer said:
leave it alone.

You've done a bad, bad thing. Could be the bolt is loctited in. It might be best to just forget it. From the looks of it you've going to have to resort to drilling holes in your bike or start hitting it.

This is from the BMW PDF.

Will replacing these bolts disturb any seals ? :confused:

Greg Masters · Apr 5, 2003

Rampant Stallion said:
I'm not sure I understand that bit above about a high temperature, low heat weld

All welding needs a high enough temperature to melt the components intended to be welded together. Oxy-acetylene, for example, does this with a hotish flame, but because it's not very hot, it's a bit slow to get the components molten. This allows heat bleed into the body of the item and everything gets pretty hot by the time you've done the weld (there can also be a problem with contamination from the flame, particularly if too much oxygen is used).

The problem is reduced with conventional arc welding, but you still end up applying a lot of heat and risk oxidation.

MIG & TIG welding is ultra high temperature arc welding in an inert gas environment. Different inert gases (Argon, CO2, Helium etc) give different arc temperatures and characteristics. On a job like this the weld can be done in about a second. High temperature to get the weld done, but low heat input so the components don't get too hot.

Greg

Bolt stuck - any suggestions ?

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