Where do I start and what special tools and knowlage do I need to overhaul std Cortina front calipers?

Any hidden snags

Before starting check out availability and cost of seals, pistons and bleed nipples. Also worth checking cost of reconditioned units, DO NOT undo the bolts holding the caliper halves together as seals are probably not available, clean exterior . Clamp one piston in bore using G clamp , use compressed air or possibly master cylinder connected and bled,press out piston, clean bore using brake cleaner, fit new seal and dust cover to bore .Lubricate seal with brake fluid, GENTLY insert new? piston to bore, repeat with next piston.

the seals aren't a big deal, brakes international sell them for a few pence. The bolts however are a different matter, they are some sort of special bolt that's done up to a special torque so as to remain in the elastic range or something (I'm not an engineer). The original caliper manufacturers specifically don't make replacements available and I think they're one-use only.

unfortunately I don't have sources for this information, but I decided to get recon ones from a reputable company and let someone else worry about it.

Front brakes - not the place to take chances imho!

[Edited on 1/2/05 by blueshift]

Darren at Dozracing supplied my recon kits - genuine units - the best.

You will probably need a grease gun to pressure the pistons out, and a G clamp to retain the first one to 'pop' while you pressure the second out. Reassembly is very easy, but please do make sure the units are VERY clean before you start. The slightest fragment of dirt will ruin the whole job.
Rescued attachment Caliper Recon.jpg