'82 front caliper - broken bolt

[BrookieDC]

Hey all,

After rebuilding my calipers, I was reinstalling them and broke a bolt. I was torquing them, but it seemed that I wasn't even coming close to the torque setting (30 lb/ft) before it gave out on me.

This is NOT one of the two bolts that attaches the caliper bracket to the fork, it's the single 8mm x 50mm long flange-head bolt that attaches the caliper to the bracket - the one that goes through the bushing, the one that makes the caliper "float".

Does anyone know where to get a replacement bolt? I want to make sure I get one that is the right specs (not too hard, not too soft). Mike's XS doesn't sell it, and the sites that sell OEM parts don't have them in their stock (Xtreme Powersports, etc). Is it OK to improvise with this bolt and get one that is not the same specs/tolerances?

Thanks in advance!

 

[Sundie]

no way is that bolt supposed to hit 30lbs of torque. My manual says 14. Anything grade 6 should do you, but i'm surprised you didn't strip the threads on the caliper carrier before you broke the bolt.

I would (if you're worried about it backing out) use blue lock-tite and just snug it up well.

 

[BrookieDC]

Thanks. My manual actually didn't have a torque for that bolt specifically - just for the caliper bracket bolts (~30 ft/lbs) and for the banjo bolts (~12 ft/lbs). I went with the torque setting for the bracket bolts, but luckily it's not stripped out. The broken end was stuck in the threaded part of the caliper bracket and wasn't difficult to extract.

I'll try a grade six bolt. Thanks for the help.

 

[Sundie]

While those bolts are larger, and can handle the 30lbs, they're still going into aluminum on the fork... I can't find the torque settings right now for those, but 30 still sounds high for fine thread into old aluminum.

Note that these don't have to be reefed in - all the force is shearing, not pulling. And i'm pretty sure the slider bolt doesn't have anything more than locating force - the caliper slides into grooves on the carrier, which carries the main shearing force when braking.

blue loctite and lock washers are your friends. For mine, i replaced the flat washers with lock washers, a dab of loctite (blue, not red. Red is crazy/i'll need an impact to get it off) and just snugged it down until the lock washer was fully compressed, then a titch more. Nary a problem.

 

[blue900]

My 82 service Manuel says caliper bolts to fork 18.8ft-lb easy does it.