Rear brake caliper bolt - help please

Hi guys, hope someone can help please...

I've just had the back wheel off to get the tyre changed, and when I have tried to bolt the rear brake caliper back on after refitting the wheel, it looks like I've somehow fubar'd the thread on the caliper for the front bolt (the one with the 14mm head) - when I tried to tighten the bolt I could only get about 3 half-turns with the wrench before the bolt stops and jams. The thread on the bolt is ok but I can see shiny bits of newly-exposed metal on the thread on the caliper which makes me think I've cross-threaded (is that the right term?) it somehow.

Is there an easy fix for this or am I going to have to replace the caliper? The bike is my daily transport to work too, so I need to fix it asap

Thanks

EDIT: it's a K5 as per my avatar by the way, forgot to mention...

[jambo]

It's not sounding great, but fear ye not, we've all managed it.

Take the wheel out if needed but make sure you can get good, clean access to the back of the caliper mounting bracket. I'm going to assume it's got a thread that goes all the way through as it does on my ZX6R, I've not fitted a caliper to a pointy before so bear with me on this.

Inspect the bolt and check it's clean and the thread looks OK. Provided it is, go in from the back of the mounting rather than the front, and gently do thread the bolt in, if it meets resistance, come out a bit and then back in, using WD40 or similar to lubricate it's running, this is often good enough to clean up a slightly scruffy thread and allow you to go in carefully from the correct side again. Make sure that the bolt goes in cleanly from both sides before you re-fit the caliper, and then be very gentle.

Failing that, thread restorers and tap & die kits can help you out.

Jambo

Ta Jambo I'll give that a try & post back with the results. Fingers crossed...

Righto, tried that 3 times and now I'm confused...

Each time, I screwed the bolt in from the back of the caliper after cleaning up the threads and when I then screwed the bolt in the correct way with the caliper off the bike, it screws in all the way with no problems. As soon as I fit the caliper to the bike and try to screw in the bolt though, it crosses up again and jams after a few turns. I have been extra careful to make sure I've got the bolt in straight so I cannot figure out WTF is causing the thread to cross up.

Think I might admit defeat and take it to a garage in the morning. I don't have a tap & die kit anyway so if it needs re-threading I've got no choice really...

I'm just mightily pee'd off with myself cos I've had the caliper off loads of times before to service it etc and I haven't done anything different this time when trying to refit the ****ing thing!!

[jambo]

Given the bolt goes in without the caliper, I'd assume that it's not lining up quite right because of some small amount of force from the caliper, and that's causing you the problem.

Can you push the pads open further than you normally would, fit the caliper to the mounting bracket wouithout the wheel in place then fit the wheel in afterwards?

I know you can do this with the curvy.

Jambo

Originally Posted by jambo

Given the bolt goes in without the caliper, I'd assume that it's not lining up quite right because of some small amount of force from the caliper, and that's causing you the problem.

Can you push the pads open further than you normally would, fit the caliper to the mounting bracket wouithout the wheel in place then fit the wheel in afterwards?

I know you can do this with the curvy.

Jambo

It can be done cos I've done it once before, but ironically enough I took the caliper off this time round to make life easier when it came to refitting the wheel! I'll give that a go and see what happens - usually ends up with me swearing a lot cos the spacers keep dropping out of the wheel while I'm trying to line everything up!

Ok, I screwed it in & out from the back (oo-er missus!) a couple more times to try & help re-thread it, then with the wheel off I re-fitted the caliper with the piston pushed all the way back into the caliper and the pads as far apart as they'll go to give the disc plenty of room to manouvre and it's all fitted back into place quite nicely. Sadly it meant I didn't have time for a ride to go & scrub the new tyre in but hey, there's always tomorrow.

Jambo - you da man!! Come & find me at the AR, there's a pint with your name on it!

[jambo]

Now worries, I'm assuming the thread is only a little awkward at the start and that there's plenty left to get a good solid purchase on for that bolt. Clearly this is not a bolt you want coming out, but from how you've described it I imagine it's fine.

See you at the AR

Jambo

[punyXpress]

Before you ride off into the dawn, just press the brake pedal a few times to get pads adjusted.
Unnerving to press the pedal all the way down & nowt 'appens.