[svxistentialist]

Seized sliders like this are common enough Keith.

My suggestion is you take off the brake pipes and remove the caliper from the wheel.

The upper and lower slider needs to be free. When you have it off is a good time to take out and polish up nice and shiny the two piston pots, and ensure they are free to move in and out of the sockets easily. If the seals are damaged, get a new set of seals and replace them.

You should be able to get the sliders loose when you have the caliper firmly held in a bench vice. If it is still difficult use heat, but after using heat you will probably need to replace all the rubber seals. You may want to do this anyway to do a proper job.

Once you have the slider pins freed ensure you have all corrosion polished off them. Then regrease and replace the dust seals if need be.

This sounds like a fair bit of work, and it is, but for sure when it is all freed up your brakes will work surprisingly well.

OH, I forgot one thing; before you remove the flexible brake pipe make sure to clamp it to stop air getting sucked into the system.

Joe