I think Nate is right, it sounds like a proportioning valve. It would have to be upstream of the drums themselves. Do the brakes feel okay through the pedal?

My gf had a ZX2 when I first met her, then her brother totaled it. I say thank goodness...I couldn't stand the thing.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth