Brake caliper

[Purplepill]

Hi, my brake caliper was sticking quite badly, and iv cleaned it all up a few times now so knew the pistons where knackered, iv now had the most use I can get from them so I decided too try my luck with a second hand caliper off ebay (piston/seal kits were out of stock and had been waiting for an order of them for ages)

Anyway the new caliper arrived, the sliders were worse condition than my origional one so I changed them over, and the pistons were pushed 100% into the cylinders so I couldnt check there condition.

So I fitted this caliper to my disk, and bled the system. Unfortunatly as soon as I got pressure at the lever, I forgot to remove the caliper again to clean pistons, and just pumped the pistons right to the disk......and now the pistons wont retract atall, the caliper is seized solid to the disk, and its IMPOSSIBLE to turn front wheel atall (literally, I had to place a stick under the front wheel just to get the damn thing off the center stand!)

Iv tryed gently tapping the outside of the caliper cylinders, and pulling like mad but it just wont budge (newish disk aswell so id cry if it cracked or something) The only way I can get the front wheel to move is with engine power, and as soon as you let of the throttle slightly the forks pretty much bottom out so this is serious its seems just as stuck even after being moved under engine power.

Im really stuck now, I cant fix this problem unless I can get the caliper off the feckin disk, what would you guys do if it happend to you? (resevoir not overfull btw)

Cheers .
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''He had the confidence of a baby-goat dared to tickle a t-rex's nutsack''

[Wil]

Drain off some fluid to allow the pistons to move, then rebleed it.
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'07 Triumph Speed Four

Aw look, a baby driving a car. And look, there's a dog driving a bus!

[Purplepill]

Sorry if I come across abit dense here, but how would the brake fluid be stopping the pistons from retracting if theres plenty of space in the reservoir? im pretty sure there just badly seized.

Cheers.
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''He had the confidence of a baby-goat dared to tickle a t-rex's nutsack''

[Cigaro]

Remove calliper mounting bolts and keep wiggling it until you free it up sufficiently to remove. Also undo the bleed nipple, this may help further.

[Wil]

Have you removed the master cylinder cap to allow the fluid to move? If not you'll be trying to compress the fluid in the system against the small pocket of air in the master cylinder. Air is easier to compress than brake fluid, but it'll probably still be hard work. I'd still go for loosening the bleed nipple, easier to catch the fluid that way rather than it overflowing at the master cyclinder end of things.
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'07 Triumph Speed Four

Aw look, a baby driving a car. And look, there's a dog driving a bus!

[Purplepill]

Yeah the M/C cover was off when I tryed. Bassjunky thats the problem lol it doesnt free up enough to move off the disk, its jammed SOLID somehow Il have another go with the bleed nipple undone soon though

(oh and off-topic, 'spares unlimited' - an ebay shop, is to be avoided, totally mis-described this caliper they said I can return it but il lose the 9 quid postage + whatever it costs me to send it back, and it was only 25 quid so not really worth it)
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''He had the confidence of a baby-goat dared to tickle a t-rex's nutsack''

[Wil]

In that case it could just be they are sticky pistons. You should only need a bit of clearance to remove the caliper from the disk, so maybe some strategic and gentle levering with a thin screwdriver is in order, although it could damage your disk. I presume there are no gaps in the disk that would enable you to get a pair of water pump pliers or a C clamp into to compress the piston into the caliper?
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'07 Triumph Speed Four

Aw look, a baby driving a car. And look, there's a dog driving a bus!

[stinkwheel]

You should be able to get a g-clamp on it and wind them back in.

EDIT:

Correction, You can definately get a g-clamp on them and wind them back in. Put the fixed part of the clamp on the outside of the calliper and screw the movable part up against the back of the brake pad. You will need to turn the wheel so you can pass the clamp between the spokes.

You might want to put a bit of rag under the clamp to stop it marking the paint on the calliper.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Purplepill]

[stinkwheel]

[Purplepill]

Do you know any online shops other than wemoto that sell piston/seal kits for them, as for some reason they only have the big piston listed and not the small one? (also tryed another online place called 'motorcycleproducts' or something along those lines but they said it could be at least a few weeks for some reason that iv forgot)
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''He had the confidence of a baby-goat dared to tickle a t-rex's nutsack''

[Purplepill]

Managaed to get it off. Turns out the pistons are in bloody good condition compared to my old ones (they were caked in crud, but at least there was no corrosion or rust like my others so cleaned up a treat)

Il finish the job tommorow as im fed up working by candlelight in the wind neibours must think im mad
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''He had the confidence of a baby-goat dared to tickle a t-rex's nutsack''

[sickpup]

pretty sure i have those in stock, what year GPZ5 is it?

[Purplepill]

Its a '97 D1 model, After seeing the pistons I can't justify new ones, however il definatly have a fluid/dust seals set off you, PM me with price and paypal/email address
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''He had the confidence of a baby-goat dared to tickle a t-rex's nutsack''

[sickpup]

Got loads in stock. PM sent.