Seized brake piston

[gordo7]

Looking for a little help in freeing up a seized brake piston. Have decided to enter my '74 XS 650 in historics racing but right side front brake (twin disc model) has seized solid. Tried the drown in WD40 and the air compressor trick but no good. Next step will be heat application.
Anybody have any ideas??
cheers
Gord.

[Semi]

you cant get it to move at all? even with the calipers off and using the lines/lever?

[bertie]

brake cleaner and a tooth brush??

[gordo7]

you cant get it to move at all? even with the calipers off and using the lines/lever?

She be rock solid!

[Semi]

Id try heating it then

[gordo7]

Id try heating it then

That will be the next trick. The fun we have working on 34 year old bikes!!

[Nero Diablo]

Did you try soaking with penatrene or similar product overnight. The Locktight freeze spray supposedly works pretty good might be worth a go.

[Semi]

IM assuming you're changing all the seals though, right?

[Rob]

You can fill it up with water, and then heat with an oxy. As the water expands, the slug should come out with a bang - best to point that into a bucket etc.

Sleeve will probably be rooted etc

[g0zer]

push it all the way in to break the stiction?

then pump it out with a working master cylinder? hook it up to the rear master cylinder?

[Marty MOOSE]

Pump it up with a high pressure grease gun

[smokeymatt]

Clamp it in a vice with pressure on the piston and see if you can squeeze it in a little to free it up. Use metho instead of brake fluid hook it up directly to the mastercylinder and see if you can pump it out. It will move, just needs the right amount of pressure. I have an old master cylinder and half a handle bar screwed to a block of wood which i use for such jobs. PM if you want ot come over and give it a go

[MattyA]

Pump it up with a high pressure grease gun

your on the money here no risk of hurtin yourself.

screw a grease nipple into the brakeline/banjo fitting an pump it up with grease i have done this many-a-time and hasnt failed my yet

[chief wiggum]

you need a bigger hammer