Topic: Stripped bleeder bolt threads in caliper...what are my options?

[Gorms]

The bleeder bolt on my cb550 was rusted pretty good.  I managed to get it out and upon reassembly, in a real boneheaded move on my part, I stripped the female threads in the caliper thinking the bolt wasnt seated enough.  I chased the threads of the bolt with a die and retapped the caliper in an attempt to restore the threads.  The top maybe 5 threads in the caliper are pretty short and rounded off from years of the previous owner screwing and unscrewing a rusted bleeder bolt with bad threads, so these top 5 threads dont really even engage at all.  Now the lower ones that did engage dont...the bolt just spins.  In a last ditch effort, I shortened the coned tip of the bleeder bolt so that it would have to screw down further to seat and use more threads to do so.  The bolt now holds and has 2.5 turns of good threads before it is seated.  Its kinda tight but I dont want to tighten it too much and strip those threads.

My question is what are my options.  I doubt anyone here is gonna say "2.5 threads is enough go ride it!".  Can I smear the top threads of the caliper with JB Weld and tap them?  Do I need a new caliper?  

[Gorms]

If I shorten the bolt further and maybe get another thread or two out of it AND jb weld and tap the top 5 threads, you think that will be OK?  When I stripped the threads, it looks like I only stripped about 2 threads, so thats all it ever had holding it in.  The top threads have always been rounded and never really grabbed I dont think.

[Trevor from Warragul]

http://www.agriemach.com/product_info.php?cPath=cPath=44&products_id=842

[Gorms]

Something like that could work except they only go up to 8mm and my bleeder bolt is 10mm.  Also there isnt much material around the hole to enlarge it.

[bikebitzofvt]

The bleeder should've been much smaller thread that 10MM if it's original.  6 x 1.00 if I recall correctly.  That is a steal on those bleeder repair kitsmentioned by morini, I wonder if something similar could be found stateside?!?

A while back someone else had similar trouble, best fix I could come up with at the time was this:

http://www.truechoice.com/prodinfo.asp?number=BLEEDER+KIT

It's a bit pricey but should fit the bill.

You're correct, likely no one will tell you to run it with scarcely 3 threads holding it (and your brake fluid) in place.
Be safe!
Tom

[Hinz]

I'm pretty sure you're mixing up wrench size and thread size.  I've NEVER seen a bleeder of any sort with 10mm threads, that's really big.

6mm threads = 10mm wrench
8mm threads = 12/13mm wrench
10mm threads = 14mm wrench

[Gorms]

Well the bleeder is DEFINATELY 10mm.  I bought a replacement bleeder from Hondaand it was way too small so I just assumed it was the wrong part.  Looks like someone drilled out my bleeder hole at one point.  Damn.  Anyone have a spare brake caliper I can have for cheap?

[Hinz]

those previous owners can be real jerk sandwiches sometimes.. 
If it were my bike, i'd just get a new-used caliper too. 
However, If you're in a real pinch...plug up the bleeder hole and bench bleed the whole shebang off of the bike.
I did a Saturn clutch like that once.  What a POS.

 

[Gorms]

Can you describe how I would bench bleed them with a plugged hole?  That way I can ride the bike at least while I wait for a new caliper.  Can I just jbweld the hole?  Or maybe jb weld my huge bleeder bolt into the hole?

[Hinz]

I would use a pipe plug or a short M10 bolt or something a little stronger than JB weld by itself.

You need to take the caliper, all the hoses and master cylinder off of the bike as a unit.  Plug up the caliper and fill the master cylinder with fluid. You want to make sure that all of this is hanging vertically so that the master cylinder is the highest part...this way all the air bubbles will float to the top.  I like to put the master cylinder in a vise so I know it's not going anywhere.  Oh and make sure the cap is off of the fluid reservoir too.  
Clamp the piston into the caliper so it's all the way in.  A regular C-clamp works fine for this.
Now that everything is hanging, start tapping on the caliper and lines with a wrench to get those air bubbles to move to the master cylinder.  
This is sometimes called "gravity bleeding"
I would let it hang overnight and check on it every hour or so and add more brake fluid if necessary and to keep tapping.
The next day, remove the clamp on the caliper and add more brake fluid as necessary. Don't let the fluid level drop too low or else you may end up getting more air in the lines.  Then cap off the master cylinder and install the whole brake assembly back onto the bike.
Just remember that brake fluid takes the paint off of anything.

[Gorms]

K thanks.  Getting another caliper isnt that big of a deal considering but I'm so close to being done with this cafe project that this is really the last thing I want.  So frustrating.

[lordmoonpie]

Just to put you at ease - my bleeder bolts are 10mm too. Standard honda parts. If you stripped the threads in the caliper itself, I'd just get it helicoiled back to 10mm. The helicoiling process over-drills and taps the hole to get the smaller wind in coil back to 10mm so it should leave you with a good tight 10mm finish. The other benefit is that the helicoil is steel so you'll have a tougher job to strip it next time.

A 10mm helicoil kit should be relatively cheap or your local bike shop might be able to do it for you. I've helicoiled up to 20mm in the past and it's a great solution to stripped threads...good luck! 

[bryanj]

Depends on the bike 750 is 10mm and all smaller 6 or 7mm. Those repair  kits are an american part made by CTA MANUFACTURING of Carlstadt NJ 07072 and for the 10 mm one (they do two sizes!!) you need part number 1235 (7mm 1230) although i think they both use the 1/8 NPT tap for the adaptor.

From the post i put up in the first place i think they were found at a NAPA store on your side of the pond, but may have to be ordered in.

I eventualy (after 3 years) got arround to putting the speeling in the post right so search for "caliper bleeder fix" for the full description