Tawraste666

Hi all,
Looking for a little advice before I get stuck in - I have a TRP spyre type C mechanical brake caliper and I have two bolts and one piston that have galled.
I have removed one bolt by drilling and recutting the thread (very carefully may I add) but I felt this was risky and lacked finesse.
I have thought about using temperature (both freezing and heating) to crack the galling, anyone had any luck with that?
Or anyone had luck in another way?
Once I get these parts out I shall take the necessary steps to stop this happening again, and inspect more frequently!
Anyway, hope someone has some info.
Thanks in advance.

soyabean

Boil the entire thing in soapy hot water in pot you won't eat from anymore, for about an hour. I do this with small engine carbs all the time.

Can also try ultrasonic cleaner. Even if doesn't work on this gig, at least you now have the unit to do all sorts of other miraculous things.

Tawraste666

Thanks! I'll definately give that one a go.

Tawraste666

Just wanted to let you know that your advice worked! Thanks a lot, you have saved me some money!
I did manage to get the brake pad pin loose by freezing for an hour, but I used your method on the brake piston as that was stuck really fast.
For those in a similar situation:
I had to boil it for nearly an hour, trying regularly to loosen it, and in the end I thought it hadn't worked. I popped it in my bench vise whilst it was still warm, applied the allen key and it suddenly popped free!
I have attached some pics so you can see the threads are not damaged. Fantastic.
I then stripped both brake calipers down to make sure nothing else was stuck and found corrosion on one of the mounting pins. Now everything is clean and treated with ACF-50 to prevent further corrosion and siezing - and no, it's not dripping, so no risk to the brake pads, just a very very light application with a rag.

Anyway, thanks again!

Both calipers stripped down and cleaned.

Mounting pin with corrosion.

Rescued siezed threads. The retaining brake pad pin released by freezing, the pad piston released by boiling in soapy water for an hour.

Tawraste666

By the way, the one that I drilled was the barrel adjuster.
Won't be doing that again!