Removal of seized caliper pistons.

[tonyabacus]

That tool at Pegasus Racing looks ideal and I wouldn't be surprised if Snap On don't have something similar, so make be worth talking to your local garage for a contact number for the local Snap On man
Tony

[Neil Spooner]

There’s more than one way to skin a cat…..personally I found the drilling and tapping of the u/s brake hose easy and quick and at no cost as I borrowed the grease nipple from the propshaft. The grease gun is standard equipment, and the low viscosity grease very easy to clean out.
Purchasing a tool that I am going to use infrequently or ever again somewhat extravagant. I very much doubt that the piston clamp would have worked in this case.
But to each their own.

[2cams70]

There’s more than one way to skin a cat…..personally I found the drilling and tapping of the u/s brake hose easy and quick and at no cost as I borrowed the grease nipple from the propshaft. The grease gun is standard equipment, and the low viscosity grease very easy to clean out.
Purchasing a tool that I am going to use infrequently or ever again somewhat extravagant. I very much doubt that the piston clamp would have worked in this case.
But to each their own.

It’s a golden rule and one of the first things you learn and you’ll see it stated in any workshop manual to never ever let any form of petroleum based oil, cleaning fluid or grease come in contact with brake system rubber. If you must use grease make sure you use a grease that is compatible with brake system rubber such as something like Castrol GRRB. Do not use any old grease.

[mikealdren]

I've dealt with badly stuck callipers a couple of times by draining off the fluid and putting in some water. I then close off the bleed and input connections and place a block of wood between the pistons to stop them coming right out and cover with a cloth to stop and fluid spraying everywhere.. I then put them in the low oven (110C) to boil the water and push out the pistons. It's worked for me, all the components can easily handle the temperature but I've been expecting to thoroughly clean the callipers and replace seals anyway.

[2cams70]

I've dealt with badly stuck callipers a couple of times by draining off the fluid and putting in some water. I then close off the bleed and input connections and place a block of wood between the pistons to stop them coming right out and cover with a cloth to stop and fluid spraying everywhere.. I then put them in the low oven (110C) to boil the water and push out the pistons. It's worked for me, all the components can easily handle the temperature but I've been expecting to thoroughly clean the callipers and replace seals anyway.

That's clever! - water won't hurt brake components.

[tonyabacus]

If you know someone with a laser cutter, it should be relatively easy to make a tool similar to that shown in the Pegasus link above. Could be made from Delrin rather than aluminium but slightly wider to give a wider grip of the piston and potential remove chances of marking the piston surface
Tony

[gjz30075]

I like the Pegasus tool but I think adding 'teeth' to the gripping surface would help. If the piston needs
to be removed with force, there's no reusing the piston.

[2cams70]

That Pegasus tool is only useful for pistons that aren't stuck. Those of you who have ever tried to remove stuck pistons using multigrip pliers will understand.

[Sadbrewer]

That Pegasus tool is only useful for pistons that aren't stuck. Those of you who have ever tried to remove stuck pistons using multigrip pliers will understand.

I agree....they can be absolutely fossilised, we sometimes used to weld a long piece of flat bar across the top of the piston, the extra leverage and the bit of heat usually did the trick...new pistons needed of course.

[gus]

YEars ago I used a friends scuba tanks to pop them out.

I would not worry about grease affecting the seals unless you leave them full of grease for a long time.
flushing them more or less immediately should clear it out.
Using the mast assumes they will move with the master, not a safe bet