Last year in TSO was a tech note from a fellow with the same problem.
He filled the cylinders with as much oil as they would hold, then screwed
in a bolt to "compress" the oil. Since the oil is incompressible, the
pistons moved and broke free.
Another approach is to modify/sacrifice a fitting so that you can put a
grease nipple in it, then pump the cylinder full of grease until the
On Mon, 8 Sep 1997 16:12:59 -0500 email@example.com writes:
>Here's a tough one:-
>I've got 12 brake slave cylinders from two MGTD's. They are ALL
>rusted so that the pistons are frozen in the cylinders. I have tried
>EVERYTHING to get these things apart, including: WD-40, Liquid
>Wrench, PB Blaster and molasses (don't ask). They are still frozen
>My next step is to get out the blue wrench (propane torch). Since the
>cylinders are aluminum and the pistons are steel, I expect that they
>will expand at different rates when heated. Hopefully, they will
>release if the aluminum expands more that the steel.
>Are my assumptions correct? Does aluminum expand more that steel when
>heated? Am I in danger of splitting or otherwise damaging the
>cylinders by doing this? Anybody got any better ideas?