Never tried it but 50/50 acetone/ATF mix is supposed to be a really effective penetrating oil, it might be worth a try.
Heat directed to the caliper to the area just below the bleeder is probably your best option. The heat gun would need have a fine point to direct it to the right place.
Quote from: unfazed on 09 April 2020, 12:40:34 amHeat directed to the caliper to the area just below the bleeder is probably your best option. The heat gun would need have a fine point to direct it to the right place. Heat the caliper body below the nipple at the same time, using a ring spanner or break nipple spanner, even a socket start to slowly apply pressure and undo the nipple, you don't need too much. It's normally does the trick, but not always, sometimes the only way is to drill the bugger out, which isn't always cost effective as a replacement caliper can be cheaper then drilling and helicoiling, certainly quicker. Oh if you're doing it while the caliper is still on the bike, make sure you don't heat the break line
I always use a blow torch, just be careful not to damage paint work with it.
Yeh, nipples are always overlooked, I give mine a twist and lube every couple of months and flush and replace the fluid every year.
I have just been shooting up Its a penetrating fluid and I find a syringe and blunt needle perfect.
I've had a crazy thought, please talk me out of it. Would it make sense to "paint in" the nipples once they're on? Stop the rust getting in. Copper grease is no good as it gets washed out during bleeding.