Although it did give me time to pop the caliper pistons out to clean & red rubber grease the seals to, hopefully, cure the sticking brake.
Thought I'd add a little more info on how I did this.
After undoing the master cylinder cap I pushed all the pistons in on one of the calipers and then zip tied two of them down using one of the pads. Pumping the lever pushed the other two out but not completely. I cleaned & greased the pistons in situ but when I pushed them back in one of them required a bit of pressure before it suddenly shot in and... yes you've guessed it the other with a smug pop shot completely out
![Surprised :o](./images/smilies/ohmy.gif)
followed by most of the fluid in the system. 'kin rs..
So this forced my hand and without any seal kits I had to press on without splitting the calipers. Disconnected the caliper & with one piston out it's seals & bore could be cleaned properly by (very) gently using the round end of a zip tie. Smear of grease on the seals & piston which could then be quite easily pushed back in.
Zip tied the cleaned piston down then used a foot pump with a cut down air bed adaptor in the caliper union hole and out popped the other. Cleaned, greased, re-inserted & zip tied then undid the zip tie on the others back to the foot pump & another pops out. Repeat until all have being done & same on the other caliper. Used a folded rag over the piston before it popped out to save it smacking the opposite piston.
And lo & behold the binding brake was cured , hoorah
Andy B