Any advice please on how to remove seized Pistons from their calipers. The brake has been unused for many years and penetrating oil hasn’t helped so far. The forums help has worked in the past for me so fingers crossed. Cheers Dougie.
Heat the calipers up with a hot air gun then plunge them into a vat of coca cola and leave for a few days.
I got mine out by levering the dust boot groove with an old screwdriver. You need to go carefully because there isn’t much lip, and work a little at a time from both sides to keep it straight. I have heard of cases where this didn’t work so the last resort is apparently to drill and tap the piston and jack out with a bolt.
Airline can help sometimes, pop into feed hole, take all safety measures tho 
I’ve had to do this. Luckily the piston isn’t likely to be right back in the bore so it’s possible. Once the hole had been drilled and tapped I filled the space behind the piston with dismantling fluid and left it for a couple of days before winding it out with a bolt.
Hi Dougie
As above and…
Which callipers? if they are 1990s models then only part of the following is true.
If they are the ones fitted to Tonti era bikes the here you go;
Have used this in the past when chrome plated pistons have seized.
1: Split calliper.
2: Lay the halves piston side up.
3: Gently warm the calliper (rag soaked in boiling water, hair dryer etc). Too much heat (blowlamp) has potential to damage the calliper body.
4: Apply brake fluid to the piston-calliper.joint and leave to soak.
5: Repeat a few times and try to start slight movement in the piston.
6: Clean, fit Teflon coated pistons and new seals etc.
If they are the later callipers you may struggle to find seal kits. Brembo stopped supplying them because of possible litigation should a rebuild go wrong 
This is not to say that 3+ above won’t work.
There is a rebuild service available for the later models. The link is somewhere else on the site.
HTH Good luck
Steve
Interesting comment about litigation Steve. I bought Brembo pistons, seal kits and bleed nipples for my P08 and P09 calipers, which all come in separate packaging, each with a massive fold-out sheet detailing how to rebuild the caliper. Filled up my paper recycling bin!
Thanks for everyone’s advice, the calipers are from an 1983. T3 and I have plenty of old brake fluid to soak them in to start with, then on to coca cola and drilling and tapping. I should have spent the extra and bought a guzzi with all the work done, I’m making hard work of this. Cheers again. Dougie.
chin up old boy, 
when its finished you will have the satisfaction of knowing you built it, 
I was seized with the sudden urge to write ‘Things go better with Coke’. Aah, that’s better. On a serious note I’ve used a bath of Coke several times to free-off corroded parts with success. I much prefer Pepsi to drink though. 
Correct Buzz.
Will you or DelBoy be bringing my mug to the clox?
You have to take your own mug Ian its attached to your boat race
totaly a tiny bit off tpic well sort of MY STORY OF ADDICTION TO COKE
ANYONE FEEL FREE TO SHARE THIS IN THE HOPE THAT SOME OF THE MANY KIDS DRINKING IT OR PARENTS BUYING IT TO HAVE A QUITE LIFE ACTUALLY READ IT AND IT HITS HOME AND THEY CUT IT OUT
12 years ago i was ADDICTED TO BOTH COCA COLA AND RED BULL i was drinking up to 4 ltrs of coke a day and 1 to 2 litres of red bull - went to Lanzarote fot 2 weeks - drank 1 ltr of coke on the plane - and thought this has got to stop - bought 1 - 500 ml bottle on route to apartment and then put it on the table - wife put it in fridge i got it out back on the table and told her to leave it there - The next 4 days were the worse in my life i was sitting in 40 degree heat wrapped up in towels actually shivering - got that bad the emergency paramedics were called - they applauded what i was doing and basically left me to it after putting a lot of fluids in me - got up on day 4 and was totally fine - to this day i have not dared to touch either one again - it has come back to haunt me as i was drinking in excess of 1/2 a KILO of sugar a day and now type 2 diabetic so beware
what mug, we will be at the clox so see you ther,
Wow, that’s an eye opener, heard of folk getting the shakes when deprived of red bull type energy drinks, but never coke. I have to say I’ve lived to my great age and never drank a drop of either, yes, I was deprived as a child…
About 8 years ago for some reason I decided to go over to de caf coffee.
I used to drink 2 mugs (plus 2 sugars) before work, 1 immediately after getting to work, then coffee break, 2 during dinner and another coffee break. First thing I did on getting home was make a coffee.
I went over to de caf (1 sugar for some reason)on a Saturday and in the shower that night I realised I had only made the 1 mug of coffee all day.
I had been addicted to the caffeine and didn’t realise it.
I lost 1 inch and 5 kilos in a very short time with no effort.
I have just managed to remove all 8 Pistons from a set of Tokico calipers on an RGV250 I have just bought. It has sat for 16 years and the calipers were locked on. After removing the calipers I split them, soaked them in penetrating fluid and used lots of heat to try and soften the seals. I bought a simple piston removing tool that is basically and expanding wedge and eventually got them all out in reusable condition.
Heat and patience were the main ingredients.
Only ever used cola to remove rust, never actually drank it so it seems I may have had a lucky escape!!
I still after 12 years tell doctor i have something wrong internally as i replaced the coke and red bull with plain water and never lost a pound
The other interesting fact is that in the old days I would drink coffee by the bucket after a good session.
Now 1 coffee is all I need.
And of course I am better looking.