E-brake problem

[rwirth@ccmpo-d.draper.com]

Emergency brake on my 1990 80Q has been sticking. My weekend
inspection revealed that the lever on both calipers is binding
resulting in brake drag *ouch*. Return springs seem OK and
I am able to manually push the lever back. The calipers are the
single piston Girlings (not sure of piston dia)
Brake cable moves freely and doesn't appear to be binding.

The Bentley does not include any info about this mechanism, how it
works and if there is any way to service it. I would prefer not to
replace both calipers if there is some relatively easy rebuild for
this.

Anyone have any info about how to repair these? 

Bob

1990 80Q
1987 Quantum Wagon