Can't get a 12mm bolt off a brake caliper?

Stooby2

STOP!!!

It's entirely possible that someone has used thread lock on the bolts as mentioned above, or some Kwik Fit air ratchet monkey has done them up to stupid tightness.

If you start heaving on it with breaker bars and stuff you'll probably round the bolt off in no time.

First off get some axle stands. Never work on a car solely supported by a jack.

Turn the bolt anti-clockwise to loosen, clockwise to tighten.

Then at the very least get one of these - (this is just shown as example, it might not be the best or cheapest around)

http://www.ebay.co.uk/itm/1-2-Drive-Impact-Driver-and-Bits-Holder-Kit-Remover-Hammer-Screw-Screwdriver-/380415447328?pt=UK_Hand_Tools_Equipment&hash=item5892871120

with a set of impact sockets - (ditto)

http://www.ebay.co.uk/itm/1-2-Drive-Impact-Driver-and-Bits-Holder-Kit-Remover-Hammer-Screw-Screwdriver-/380415447328?pt=UK_Hand_Tools_Equipment&hash=item5892871120

You put the socket on the driver (don't use the screwdriver bits!), the driver on the bolt, set it to undo (read the instructions) and then hit the end very hard with a hammer. It will shock the bolt loose. You may have to hammer for a while.

If you're rich and want to do this a lot - then something like this - (ditto again)

http://www.ebay.co.uk/itm/24V-LED-light-Cordless-Impact-Wrench-1-2-Driver-2x-24v-Spare-Batteries-/221186066562?pt=UK_Home_Garden_PowerTools_SM&hash=item337fb78882

But are you sure that the caliper needs to come off and are you undoing the right bolts to do it? Many pads are held in with pins across the top and you don't need to remove the caliper at all, or you undo one of the sliding bolts and take half the caliper off...all sorts of variations. If you're not working from a manual, I'd suggest you stop, get one and try again.

londonTiger

just tapping the bolt with a small hammer gently can help unsieze bolts as the vibration loosens up the rust.

also you may try using a cheap torque wrench and tap the wrench with a bit more power by gently anti clockwise to get the bolt to come off.

when re-insertingthe bolt, put some anti sieze on the threads for next time

Norman_Castle

also you may try using a cheap torque wrench and tap the wrench with a bit more power by gently anti clockwise to get the bolt to come off.

If you've got a torque wrench, save it for correctly tightening nuts.

colino

Never came across a caliper bolt that didn't come off with a good heave on a breaker bar. They're one of the fixings that will have been undone on a car at a reasonably regular basis and I fear if it's a big issue for you, it's either already been graunched, or you need a little external expertise to put it safely right for you.

Wig

I have the same car and I can confirm:

• The caliper has to come off
• Doing it by my method he will not be under the car so will not be at risk, but he should put an axle stand under the chassis behind the removed wheel arch, and lower the jack slightly onto the axle stand.
• There is no doubt in my mind doing it with a bar and impact socket, it will come off, there is no need for an impact drive.
• There will be no rust on the thread, but there might be a white powder corrosion.
• Clean the thread of the removed bolts, re-fit and remove the bolts a couple of times to clean out the thread hole. Finally, replace the bolt with a bit of copper slip on the thread.
• The OP has not come back

TrickyWicky

gilbert_and_sullivan wrote: »

Ebay for Plus Gas if there are no motor factors worth bothering with round your way.

Ah ok, I didn't think that kind of stuff was allowed in the post (probably due to the word gas lol) so I will have a look - cheers!

gilbert_and_sullivan wrote: »

Firstly i don't buy tools needed for high forces at Halfords, secondly a 12 sided socket will easily round off a tight nut/bolt and will stretch over time unless very well made, thats why 6 sided are used for Impact and Professional quality sockets.

Tip...avoid Chinese made tools when they absolutely must not fail.

My halfords Vortex sets have been faultless along with the flexible ratchet spanners - both of which are made by a company called GearWrench in the USA and simply sold under multiple brands anyway. GearWrench (like snap on) offer a lifetime warranty on their tools including moving parts and ratchets - it's Halfrauds that try to cheat you out of the moving parts.

I've never had a problem with the Vortex or my 12 sided Draper sockets. To be honest I've been very impressed with them so far.

As for chinese tools.. I'd say the same about anything if its cheap. Market stall tools are the worst, terrible quality sockets that are like cheese. When you use those sort of sockets and they round out it makes you think the more expensive ones will and you'll waste your money buying them. Of course the opposite is true, the more expensive they are the better quality they are. It took me three months to convince myself to buy my draper socket set as I thought it was an expensive risk Truth be told its paid for itself many times over.

skivenov

londonTiger wrote: »

also you may try using a cheap torque wrench and tap the wrench with a bit more power by gently anti clockwise to get the bolt to come off.

Nooooooooooooooooooooo

A torque wrench is a tool for tightening fixings to a measured amount.
A breaker bar is a tool for cracking off tight fixings

If you (ab)use a torque wrench for swinging off tight fixings to loosen them, you will effect it's accuracy, and therefore the safety of any fixings you torque with it in the future.

Like a fair few people on this thread, I've got some very nice 12-point socket sets (my workaday set is a Draper Expert, and I like it a lot).

However, if I'm approaching a fixing that looks stubborn, I don't use any of them, I use a cheap-ish set of 6-point impact sockets, because they won't damage the head of the fixing, and if I have to, I can bash them onto a damaged fixing, which they will then grip, whereas a 12-point could well cause extra damage.

cb1979

Try you local Eurocar Parts for Plus Gas,the best stuff available for rusted items, and the impact screwdrivers are a must for any DIY Toolbox,along with a set of 6 point sockets, some 6 point sockets have quite a large chamfer in the end, i have a few with the end ground down to remove the chamfer so you get more socket on the bolt head for maxium grip

And always use axle stands before you remove any wheel, never trust a jack when you are under a car

forgotmyname

londonTiger wrote: »

when re-insertingthe bolt, put some anti sieze on the threads for next time

MMMMM NO..

Dont use anti-seize on bolts that hold the calipers on.

Thread lock yes.. Lubricant NO...

Having the bolts from a caliper fall out is not something you want to experience.

Flying-High_2

Already been mentioned..... but I think your going the wrong way with the socket . if your sat looking at the hub sweating giving it beans to your left then its the wrong way.