Getting a brake off

[Joe24]

The front brake on the Giant is stuck in the forks, and i need to get it off to put a new one on.
The brake keeps sticking on, and ive had penetrating sprey put on it, stuff that was stronger then WD40, ive taken the spring off and then put more tension on(do this when the back one does it and it works) changed the cable, inner and outer. The thing still sticks on.
When the back one kept sticking, i took the brake off, loosened the middle bolt slightly and wiped everything on the brake, put some more spring tension on and the brake was fine.
Not working with the front one, so im going to put a new one on.
How can i get it off? My ideas are:
Cut as much of the brake off as i can so i can wack the bolt out.
Drill out the brake nut bit at the back(sunk into the forks, if you get what i mean) with the big pillar drills and clamp the forks.
I cannot turn the bolt, its had longer allen keys in(took it to someone in the club) and he couldnt get it out.
So, its stuck. How should i get it out?
Cheers

 

[bonj2]

don't mean to teach you to suck eggs but:
tried a torque wrench?
if so what length/i.e. what torque have you applied to it
pipe on the end?

i use my BBB one for getting my brake off even though i only do it on 8Nm and doesn't feel very tight at all, but it feels uber tight when i go to unscrew it with an allen key

 

[fossyant]

Oh no TLC going on here then..

So will the calliper not come off the fork crown ? What's the Fork made of.....before we start advising stuff....

If you can take the whole calliper off, do it........... sorry your explanation sounds like blind panic.....

 

[skwerl]

I'm having trouble understanding how a torque wrench will help undo a bolt but...

If it's really stuck and it sounds like it is, the easiest way is going to be to drill out the back 'nut'. Sounds like it's corroded in place. They're usually about 20mm long.

When you put the new one in make sure you put some copper grease on! I then squirt a plug of silicon grease over the end of the back nut to seal it from all the spray that heads up there. Also smear some up from the underside of the steerer tube

 

[spandex]

If you do not intend on keeping the brakes? just rip off the arm if it will not come hit it hard it will come. Than to get off the brake boss just use some mole grips and clamp them on as tight as you can and spin it will come off.

 

[bonj2]

I'm having trouble understanding how a torque wrench will help undo a bolt but...

it will apply more torque than you can apply using an allen key. would've thought that was fairly obvious. whether that increased torquewill be enough we don't know.

 

[John the Monkey]

Joe has an SCR4, as I recall, so the fork should be chomoly steel, shouldn't it?

 

[bonj2]

could just change forks?
might have some spare ones knocking bout

 

[02GF74]

you don't say what brakes you are removing but from what I can gather, these are cantilever or V-brakes that are held to the fork bosses via a allen head bolt - correct?

and the bolt being steel as well as the boss, they hafve corroded like the spice girls song, become one.

perserve with the penetrating fluid - not wd40 - and maybe apply some heat, not so much that the paint will come off but you can get it pretty hot before that happens. you want to scrape the rust between the bolt/boss interface in order to get the oil in - this may require cutting the washer/brake lever to gain access.

one of the following will happen, in order of likeliness
1. the hex in the bolt head rounds off
2. the bolt snaps
3. the bolt comes undone
4. the brake boss snaps
5. the forks snap

very likely you round off the hex to you would need to drill the remainder out - clamp the fork in a drill press so it does not move otherwise you risk snapping the drill in the bolt and that is even harder to drill out!! use lots of cutting oil and start with small dirll to work to bigger ones in 1 or 2 mm steps - usually you can get a hole large enough that the bolt loosens its grip and can be unscrewed.

good luck and let us know how you get on.

 

[Ivan Ardon]

You need tools, proper manly power tools.

My weapon of choice would be a cutting disk on an angle grinder and go straight through the brake near the fork crown, then drift the remainder out from the front.

Far more satisfying than pussy footing around with allen keys and penetrating oil.

 

[skwerl]

it will apply more torque than you can apply using an allen key. would've thought that was fairly obvious. whether that increased torquewill be enough we don't know.

not obvious at all, a regular socket wrench is just as useful. More torque is likely to strip the flats anyway. 5mm allen bolts aren't meant to take heavy torque

 

[bonj2]

not obvious at all, a regular socket wrench is just as useful. More torque is likely to strip the flats anyway. 5mm allen bolts aren't meant to take heavy torque

you've answered your own confusion.
torque wrench applies a decentamount of torque,
but limits it to a sensible level (i.e. a sensible level which isn't likely to strip the flats)

 

[skwerl]

I'm not confused but I am bored now. Suffice to say that going to the lengths of using a torque wrench to undo something is daft. Engage brain and use common sense is a much easier way to go. All related to the same discussion about even bothering with a torque wrench when it comes to bikes.

 

[bonj2]

jsut thought i'd mention that that's what I personally use for that job on the off chance it might be helpful to joe..
it's the best thing for me because it applies more torque than an allen key and my socket wrench is the wrong drive.

If you don't feel that using a torque wrench on a bike is necessary because ofthe fact that you haven't got one, then you don't need to use one, and I'm not trying to impress on you the necessity of using one or trying to tell you that you should. if you're no longer confused then there is no problem, so lets just leave it at that - the OP can take what he wants from the suggestions or not as he sees fit.

no hard feelings eh

 

[skwerl]

fair enough