parking brake mechanism stuck

[Kenneth Keith]

200q20v'ers,

So I'm working on all kinds of different things on this stone gray 200q20v.
I'll keep the threads separate.  The parking brake barely engages way at the
top of the lever travel, so I get underneath thinking I can just tighten the
adjustment at the Y connection and find that the driver side caliper parking
brake is stuck in the fully applied position, but there's actually no
braking going on.  The passenger side seems to not be locked in the fully
applied position, but I didn't see if it was frozen.

I took the driver side rear caliper from my wrecked pearl 200q20v parts
stash, which I planned to use with a 280mm rear brake setup on my eS2
project, but that parking brake seems to be frozen in the non-applied
position.  I can force it back and forth, mimicking the parking brake
cable's action with a pair of channel locks, but basically the return spring
doesn't seem to be able to overcome the mechanical resistance to release it
on its own.

I looked at some stuff online to see what the rebuild kits were comprised
of, and it's just seals and boots; nothing really for the parking brake
section.  I'm wondering how I can resurrect these calipers, parking
brake-wise, so that they function as intended.  Seeing what's involved in a
rebuild, I'll end up rebuilding these, but I'm wondering if the parking
brake mechanism can be freed on these un-rebuilt calipers (particularly the
one on the car without having to bleed it tonight), or if that can only be
fixed while doing a full rebuild, then what needs to be done in addition to
the cleaning and seal/boot change?

Can I just spray Liquid Wrench on the outside and keep working the action,
or is there something inside I need to do to have functional parking brakes?

Also, for those of you that work on the rear calipers, what tool do you use
to unscrew the piston and where can I get it.  I just checked
samstagsales.com, toolsource.com and zelenda.com and didn't see what I see
in the Bentley.  Everything has pegs, but the piston surface has two
V-shaped areas rather than peg holes, so it seems like the correct tool
would have the matching shape.

Cheers,

Kenneth