T55 bolt stuck: Citroen c3, help!

Penetrating oil won't help, heat would. Undo the nipple with the caliper bolted on and a good quality socket, preferably with a T handle. I did this exact job on a Picasso the other day. First off remove the bolt you can, turn the steering to get max access. Check that the torx bit will go right to the bottom of the bolt, some torx bits have a round nose that it may well help to grind off flat, hammer the torx bit into the bolt, now you need to do two things at the same time, turn the torx bit the right way AND lever the caliper holder in the same direction, the caliper holder can only move a few millimeters but that is enough to persuade the bolt to start moving, after that there will be little difficulty undoing it the rest of the way. New bolts is always a good idea and usual manfr. recommendations on safety grounds, but I wouldn't be scared of re-using the old ones since

99.9 per cent of the time they are just put back, there is threadlock on new ones, there will be some left on yours.

No, the correct threadlock should be shiftable with hand tools.

That's very good advice- Torx, allen or spline bolts usually only round out if you use crap tools or there's dirt in the socket so the tool doesn't fit properly.

The replacement bolt thing is usually because of the threadlock. The manufacturer specifies new bolts with the correct locking compound on: If reusing them I'd be tempted to get some low-strength threadlock on, though I'm sure many don't bother. I'd get the bolts if they are in stock, for peace of mind. If not, use threadlock.

PLus by the time you've sworn at them this much the head will be knackered. Really walloping the bit in helps a lot!

Fred gurgled happily, sounding much like they were saying:

Have you tried putting a bit of steering lock on...?

When I got fed up of getting nowhere fast, I came indoors, posted my message, and had a rest from it. A friend phoned and he suggested heat too but I was reluctant to do that because there is a rubber gaiter close by. Would a soldering mat like you use for plumbing help protect the plastic? It seems counterintuitive to use heat; I would have expected it to make the bolt expand and bed tighter.

Anyway, after an hour or so I went back outside and by adopting a "press up" position, I was able to put enough weight on my arm to finally move it.

The suggestions to turn the steering would have helped enormously; why did I never think of that? I'll remember that for next time.

Without looking I'm not sure of the shape of it but I suspect it may be rounded. I'm sure part of the problem was that there seemed to be a bit of play in it. So I just need to grind it to a square edge? I never thought of helping it in with a hammer: another good idea for next time.

By the way, when removing the discs what hammer do you use? I used a mallet, the idea being that it wouldn't damage the discs so if it all went wrong I could put everything back together and drive for help. However that didn't do the mallet any favours. If you are confident there won't be problems can you hit it with a club hammer? I'm thinking it will come off quicker with a heavier blow?

I hadn't heard that before but I am an amateur ;) Curiously the Citroen dealer had not heard of it either, which is why I never bought any from him. I suppose could get him to order some and change them over one afternoon.

The bolts looked very clean and had some blue on the end, which I guess was the compound. If re-using, as I have done, is it best to leave alone or should I have added more thread lock? If so which? The other reply implied there were different grades to use.

Thanks everyone for your fast replies.

As big a f*ck-off metal one as I have. I've never failed to get discs off so I take the view that I don't care if they get a bit bent on the way off.

A large copper hammer is the nicest for the job of removal.

Heat works on really stuck bolts, it almost seems to give a lubricant effect at really high temps.

Mostly any threadlock will be fine, but I would not panic about not adding any more to what was left, a new set of bolts would not hurt and could easily be added at a later date.

Indeed. I constantly piss myself laughing watching people braying the shit out of something with a friggin claw hammer when one tap with a

5lb lump hammer would have done the job.

A claw hammer is meant for joinery and building work and should stay there.

Oh I dunno, it can be very useful for pushing back brake caliper pistons. The claws are often just the right width to fit at an angle between the protruding parts of the brake pads. Then swinging the handle levers them back in a nice controlled way.

I think you were right, I should have used a metal hammer rather than my mallet because there's not much mallet left now ;)

I find that discs sometimes need a bit of three-in-one sprayed to loosen them because they rust on but a few whacks with a hammer and there are off soon enough. I think, though I know some will disagree, the tiniest amount of copper grease on the new ones might help to prevent this next time.

It was silly of me really. I didn't want to whack the discs with a big hammer so that I could keep the old discs on and drive the car if something went wrong, but of course something did go wrong: the bolt got stuck and having the old discs in pristine condition didn't help with that. Like you say, nothing should go wrong removing the discs, so next time I'll use a heavier hammer and get the job done quicker.

BTW, any reason it has to be copper?

I didn't add any but since the bottom of the bolt had an inch of blue, I assume it has enough left on from before. I will order some new ones to change another day, just in case they have been rounded out by my efforts.

Thanks again everyone.

A copper mallet is nice to use for many reasons, the danger from flying fragments is reduced, the grip of the copper reduces the likelihood of bouncing off and hitting anything else, no danger from sparks. Just a nice tool for the job all round.

... not to mention being nicer to your wheel bearings than a damn great lump hammer. A shot hammer or leather-faced hammer good too.

I had heard that copper didn't spark. I didn't know that it didn't bounce (why?). When you say less likely to cause fragments, is that fragments from the hammer or fragments from the disc? Why is that?

Whatever the reasons, Ill add one to my shopping list for next time.

Thanks again.

The copper acts as a crumple zone and deforms around the harder steel of the disc. For the same reason the risk of bits of disk coming off is less, the bits of copper that do come off seem to be much less violent than steel. The grippy effect means less bounce/rebound. Once you have one, a copper hammer becomes the hammer of choice for most engineering tasks.