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Nipples
Hellfire - 19/6/08 at 06:28 AM

Whilst attempting to bleed the front Hi-Spec calipers last night, one of the bleed nipples snapped, leaving the bottom half of the nipple stuck in the caliper.

Decided to use a stud extractor to try and remove it (in the hope that it wasn't too tight) and yep, you've guessed it - that snapped too. So now we have half a nipple and the end of a stud extractor stuck in the caliper.

Does anybody have any ideas how we could extract it? I guess we could try spark erosion but would it also damage the caliper, or would it be more cost effective to buy half a caliper from Hi-Spec? (if at all possible)

Phil

carlknight1982 - 19/6/08 at 06:35 AM

take it to local machine shop and ask them to remove it for gotyou, I did and it only cost me a tenner

worX - 19/6/08 at 06:57 AM

Attachment for a Dremel to cut a slot in it? (for a screwdriver)

Steve

Mr Whippy - 19/6/08 at 07:55 AM

quote:
Originally posted by worX
Attachment for a Dremel to cut a slot in it? (for a screwdriver)

Steve


Unfortunately very unlikely to work as the bleed screw is still tight on the threads. Concentrated heat form an oxy torch might slacken it off but I'd just leave it to a machine shop. Afterwards do what the bikes do and replace them with good quality stainless ones.

Nosbod - 19/6/08 at 08:01 AM

I guess it depends how good the extractor is. If it is good quality then it should be very hard and you wont touch with any HSS bits either in a dremel or drill etc. You could try using carbide bits or EPOC cutters but there is no guarantee on a successful result.

If you decide to resort to sparking i'd be more than happy to do it FOC if you want to post me it. It won't damage the caliper if setup correctly. (only problem is i go away on holiday for a week as of Friday).

After sparking you sometimes need to run down the thread with either a tap (but can usually get away with a spare screw) to remove any small shards stuck in the thread.

Chris.

graememk - 19/6/08 at 08:51 AM

hope you get it out in time for newark

mike smith1 - 19/6/08 at 09:46 AM

Phil

I have a carbide drill bit you could try, let me know.

Mike

britishtrident - 19/6/08 at 10:49 AM

From the list of get out of jail free tricks.

(1) Bleed the rest of the system.

(2) bleed the brake line to the caliper as much as you can through a union -- using an assistant to work the pedal or an Eezibleed just loosen the pipe union on the caliper a crack get the assistant to push the pedal down and hold it down while you tighten he pipe. Then repeat the process three or four times.

(3) Remove the brake pads then get your assistant to pump the pedal until the pistons almost touch the disc.

(4) Push the pistons back pushing fluid and any air back to the reservoir.

Repeat steps 3 & 4 a couple of times.

(5) Re-fit the pads.

[Edited on 19/6/08 by britishtrident]

Hellfire - 19/6/08 at 11:21 AM

Gents,

thanks for your kind offers of help. We're not sure whether there's actually any air in there, so we'll bleed the rest of the system first before deciding on our next move.

If it is still a problem after bleeding and needs to come out, we may well resort to spark erosion, in which case we may be in touch Chris (Nosbod).

Thanks once again.

Phil

flak monkey - 19/6/08 at 11:38 AM

This is why wilwood calipers have a brass insert in where the bleed nipples screw in, makes it a lot easier if a nipple shears off or someone wrings the thread!

britishtrident - 19/6/08 at 02:15 PM

You can buy the brass insert to fit as repairs for broken nipples ---

http://shop.agriemach.co.uk/product_info.php?cPath=63&products_id=868 Rescued attachment BleederKit.jpg
Rescued attachment BleederKit.jpg

Nosbod - 19/6/08 at 04:39 PM

No worries Phil, good luck with the bleeding.

quote:
Originally posted by Hellfire
Gents,

thanks for your kind offers of help. We're not sure whether there's actually any air in there, so we'll bleed the rest of the system first before deciding on our next move.

If it is still a problem after bleeding and needs to come out, we may well resort to spark erosion, in which case we may be in touch Chris (Nosbod).

Thanks once again.

Phil

cjtheman - 19/6/08 at 09:17 PM

hi
phil
i think spark erosion would be your best option it happened to my cbr 600 exhaust manifold stud had it spark eroded
it was that good that i didnt even need to run a tap down through the hole as it cleaned it right up just screwed new stud in not the cheapest option cost me £30 but well worth it mate
cheers
colin

owelly - 19/6/08 at 09:28 PM

If the caliper is ally, I'd advise against using stainless nipples. They'll corrode quicker and when you come to unscrew the nipple, if it doesn't snap, it'll rip all the threads out with it.
Is it not possible to get the MiG at it and build up a blob to weld a nut to? The heat helps to free things but it doesn't get hot enough to feck the seals.
I did a proper bodge on a rear caliper (an Pug 309 GTi IIRC) when the bleed nipple sheared. I drilled and tapped another hole next to it....

NS Dev - 20/6/08 at 03:41 PM

as others have said, spark erode it or leave it in.

Unfortunately (as you now know! ) easiouts usually snap off, they are only really for winding out an already loose bolt etc.

Spark eroding it isn't a bad job, just need a die sink eroder and some copper bar for the electrode.