Brake calibre pin breakage

[King Rat]

02 bike GS 1150. BMW marked calipres with the screw in central pin. One side perfect. The near side has not fared so well. The Torx screw has fractured off. The thread was free, it is the other, plain end, that has stuck and trying to drive it out doesn't work either.

Anyone got any ideas that could help please - i have a couple of thousand miles left on the pads....but I use the bike as my transport, not a toy and need it to get to work. Bear in mind that my workshp is not even as luxurious as a pavement on yard. I have the joys of a hard core lane to work on. So thought of power tools and anything fancy like that are unavailable to me. hand tools only.

I have wondered if it is possible to drill the remaining end (the thread socket for the end of the pin that came out would act as a guide) and then a reverse thread stud remover might work perhaps. I have left the remaining part of the pin to soak in ACF50 and the pads move freely. The thread was clear and the end of the pin that fractured off came out very easily. I cannot understand why it broke.

Any help greatly received.

 

[Steptoe]

How much of the broken pin is left stuck in the caliper ?

Can you get a small pair of mole grips on what's left of the pin and move back and forth to free it ?

 

[(RIP) Kaister]

buy a vice from ebay

bolt it to the kitchen worktop or dining room table

take the caliper off

belt 7 bales of shit out of it with a big hammer

go in the warm and do it.

 

[The Grey One]

How much of the broken pin is left stuck in the caliper ?

Can you get a small pair of mole grips on what's left of the pin and move back and forth to free it ?

Won't work if you got your mole grips from the pound shop!

John

 

[MattW]

Won't work if you got your mole grips from the pound shop!

John

+1 good quality mole grips are a must for something like this.

Heat may also help - the alloy of the caliper will expand more than the steel pin and may help to break the corrosion bond. Get plenty of heat into it before trying to drift it or manipulate it with molies - you don't want to mushroom what's left of the pin and make it worse...

 

[karlp]

buy a vice from ebay

bolt it to the kitchen worktop or dining room table

take the caliper off

belt 7 bales of shit out of it with a big hammer

go in the warm and do it.

then replace dining room table

 

[karlp]

+1 good quality mole grips are a must for something like this.

Heat may also help - the alloy of the caliper will expand more than the steel pin and may help to break the corrosion bond. Get plenty of heat into it before trying to drift it or manipulate it with molies - you don't want to mushroom what's left of the pin and make it worse...

and to make it even better

get one of these freezer sprays (usually used for plumbing) and spray on the pin whilst heat is applied to the caliper.

Pin will contract and caliper will expand

 

[B4ndit]

I had to do this on a Suzuki recently. I know its not the same bike but it might help. I ended up cutting the pin level with the caliper and then drilling the remainder out.

I removed the caliper from the bike. I used the okay side as a guide for the drill. Even with that the drill went off at a slight angle. The caliper is made of a very soft material so its easy to drill it inadvertantly.
All ended well. The pin moves slightly anyway so a bit more play hasn't made any difference. That was a good thousand miles ago and all seems well.

 

[King Rat]

Thanks folks - I soaked it overnight with ACF50 and this morning the remainder of the pin drifted out easily. I used a bigger cloutie!

Now, the piston on one side is seized - one side of the calipre, not one whole calipre. I am hoping if I pack the good pistons with a new pad and use the lever the pressure might move the stuck piston...or is there another procedure I should use? Soak the pistons with brake fluid and maybe a bit more of the cloutie work again I am riding on one brake at the moment - it takes a bit longer to stop and is rather spongy, but what do you want brakes for anyway? They only slow you down. I haven't any option - I have to have the transport...so taking the line of least resistance and going earlier to make up for the more gentle attack on the road.....methods that can be performed on the bike and with minimal disruption are the best for me. I prefer to keep things working rather than have to do repairs like this. Obviously washing the bike twice a day through the winter wasn't good enough with the amount of salt thrown about.

Stuck calipre piston tricks now please...mine is just to soak and hope I can free it, then clean around. I bet I have to take the caliper off the leg... that is major surgery for me! Brass suede brush at hand to act as gentle wire brush to remove the offending crud and corruption.

 

[monkeyboy]

Thanks folks - I soaked it overnight with ACF50 and this morning the remainder of the pin drifted out easily. I used a bigger cloutie!

Now, the piston on one side is seized - one side of the calipre, not one whole calipre. I am hoping if I pack the good pistons with a new pad and use the lever the pressure might move the stuck piston...or is there another procedure I should use? Soak the pistons with brake fluid and maybe a bit more of the cloutie work again I am riding on one brake at the moment - it takes a bit longer to stop and is rather spongy, but what do you want brakes for anyway? They only slow you down. I haven't any option - I have to have the transport...so taking the line of least resistance and going earlier to make up for the more gentle attack on the road.....methods that can be performed on the bike and with minimal disruption are the best for me. I prefer to keep things working rather than have to do repairs like this. Obviously washing the bike twice a day through the winter wasn't good enough with the amount of salt thrown about.

Stuck calipre piston tricks now please...mine is just to soak and hope I can free it, then clean around. I bet I have to take the caliper off the leg... that is major surgery for me! Brass suede brush at hand to act as gentle wire brush to remove the offending crud and corruption.

Get a cheap GClamp from B&Q, that makes it easier to apply even pressure to the piston cos they get stuck if you apply uneven pressure with mole grips for example.

I've got some red rubber grease in the garage that you can put on the piston before you push it in - I could send you a bit next week if you wanted.

 

[King Rat]

g clamp - briliant, thanks. I hadn't thought of that - i have some! nice cast metal ones that are about 40 years old and as good as the day they were bought, plenty of grease on the thread you see! Even the wobbly foot is still working after all these years - only used them on wood.

That should do the trick...free one piston inwards and possibly the other outwards. If I can't get it free, yes please, 5g of red grease would be useful - if you say what it is (if you know) I might be able to get some from friendly garage man down the road!

 

[Packer]

Push the good pistons fully into the calliper. Put a block of wood between the opposing pair that move OK. Use a clamp or wire the single remaining good piston in place and try the handlebar lever.

If it doesn't want to move I would then pour very hot water over the offending area of piston/calliper and try again with the lever. The brakes are designed to function above the boiling point of water so it won't cause any damage. Others may disagree with this but the water will only cause a problem if it gets to the fluid (unlikely) and it's easy to bleed a few hundred mls. of fluid through the calliper assuming that the bleed nipples aren't seized. Which they probably will be.

When you have it freed up and cleaned, an old toothbrush with brake cleaning fluid is good, lubricate with a thin smear of rubber grease/lubricant along with all the others on both sides.

In the past I have fitted guaranteed good second hand callipers from Motor Works, advert on the head of this page.

 

[monkeyboy]

g clamp - briliant, thanks. I hadn't thought of that - i have some! nice cast metal ones that are about 40 years old and as good as the day they were bought, plenty of grease on the thread you see! Even the wobbly foot is still working after all these years - only used them on wood.

That should do the trick...free one piston inwards and possibly the other outwards. If I can't get it free, yes please, 5g of red grease would be useful - if you say what it is (if you know) I might be able to get some from friendly garage man down the road!

Like the other bloke says - block the other pair of pistons with a block of wood to stop them popping out! Red Rubber grease is for lubricating brake pistons. You local garage might have some but as long as the piston is clean you should be ok.- I'm out the country till Mon but could send you some then no problem. I've got enough for a small army and only ever used a tiny bit