Seized front calliper

Twostage

I'm going to re-spray my Alu road bike so I stripped it down last night. One of the barrel adjusters had seized so I had to drill that out. Remaining problem is I can't get the front callipers off the fork (carbon with Alu steerer). The bolt just won't budge. I left WD40 soaking round the head end all night and still stuck this morning. Sprayed WD40 round the calliper end this morning to see if it that frees it when I get home. Is there anything else I should try ?

My plan B is to simply mask off the calliper.

Yossie

Drop the forks out, drill the back of the barrel nut off, the caliper will slide out. You can the get the rest of the bolt out by either leaving to soak in a load of penetrating solution (NOT WD - different stuff), putting the caliper in a vice and using pliers to grip the nut thing or cut it off using a Dremel/hacksaw blade.

Leave it soaking for a couple of days.

If you are careful you'll get away without damaging the thread, otherwise just run a tap up it and it'll be fine.

Also try heating up the remains of the barrel nut - hot air gun/small blowtorch will do the job

When you fit the new one remember to slap loads of grease on and torque up properly.

You should be dropping the forks and bearing races off anyway for a respray otherwise it'll look gash.

andy_f

Plusgas is far superior to WD-40 for removing stuck nuts/bolts. As Yossie says a little bit of warmth is always a good option.

Twostage

Got it off. Thought I'd try loosening it by twisting the brakes back and forward and realised I could just twist it off completely.

In the meantime I'd been looking on the web for decent penetrating oils. Turns out the most effective is a 50:50 mix of automatic transmission fluid and acetone (nail varnish remover). Someone had actually done a test on seized bolts with a range of products and the AFT mix needed the least torque.