broken bleeder screws

[Guest]

Rear brake was not realeasing.

Took caliper apart. Everything came out except for the bleeder screws. They broke while I was using a socket and ratchet wrench on them.

After searching this site, found the recommendations of:

1. soaking offending screw with appropriate penetrating fluid (PB blaster,Creep, 50% acetone and ATF, etc)
2. rapping screw to break corrosion loose
3. freezing with commercial product or canned air turned upside down and/or heating with torch.

I have some concerns about heating. What is the possibility of warping the caliper? I imagine if you get it hot enough the paint will burn off; besides repainting. is that a bad thing?
I looked up the melting point of aluminum, 1220 some degrees, so with any torch I have that would not be a problem.
Would I heat the caliper around the screw or the screw or both?

Any other suggestions?

 

[Nessism]

GOOD LUCK!

I tried to extract a broken nipple from a caliper body one time and failed miserably. I suggest shopping for a new/used caliper.

 

[Brendan W]

Success rate for that is low, so low that you can't screw it up much worse than it is now.
I would soak it in a bath of 50:50 kerosene and acetone, lightly tapping it, for a few days. A screw extractor on a reversible hammer drill might shift it if you can find a good centre.
Aluminium expands about twice steel so heating could help. I would soak the entire part in the oven to maybe 400F for at least half an hour , brakes can handle that no problem.

 

[Guest]

The caliper may be able to handle it but I know my wife will not!

Thanks to both of your suggestions!

 

[Guest]

It already is center punched since it has a hole.
I'd try a bunch of heat and an easy out. Start with a small drill bit and work up to the one for the easy out.
Get that sucker HOT!

 

[Chris G]

Maybe try this idea, pictures is just an example you would need to get the core t size, I had the same issue on my XJR bleed nipple was a definite breaker, so left it be and fitted one of these job done.
if the banjo connection to your caliper is at the bottom using one of these might making bleeding a bit tricky, but you could always remove and rotate the Caliper so it's at the top to aid bleeding, then refit as normal.

just realised you have broken the nipple, if you fail to remove the broken nipple and it becomes non functional maybe you could re tap it and and fit a blanking bolt, then fit as pictured, by then it may be easier to source a replacement, good luck.

 

[JEEPRUSTY]

You should make friend with a machinist or someone with a drill press and vise.

 

[storm 64]

Western Pennsylvania... Where abouts in western Pennsylvania? I might be able to help you.

 

[Guest]

Well, so far heat has not worked out. I heated both with a mapp gas torch until the contact thermometer read 400 degree F. Sprayed and reheated. Used vice grips to try and turn the bleeders, neither turned.

Since then (about three days ago), I have been soaking them in a 50/50 mixture of acetone and ATF. Plan to try again just for the experience.

Meanwhile I bought a used caliper off ebay. Took it apart and looks like I will be able to have a usable caliper once it is cleaned up. The bike has been sitting for the summer due to a high idle problem which just wass solved and want to get some riding in before the weather turns.

 

[Grimly]

Sometimes you get one that is so corroded in it just won't release and will snap, whatever you do. I don't even try to undo them now without heating them first, unless it's on a caliper that's been serviced in the past couple of years.

 

[Guest]

After this experience, I would agree. Best to be patient and assume it is badly stuck than to grab a ratchet and break it off.

I wish I had been more patient.

Managed to clean and install the used caliper I bought using the better of the piston set from the calipers with the broken screws. I have not given up getting the screws out. If I mange will post how.