Strange brake issue

[hayesbd]

I searched for posts for this problem but came up empty. The issue is this:
Over time, one master cylinder reservoir level starts to go down while the other one goes up, even to the point of starting to spill out the cap. I'm not losing any fluid - it's just transferring from one reservoir to the other. Has anyone encountered this issue? I suspect that my new master cylinder is not up to par since there is very little brake dust from the rear brakes so that may be the main problem. Or is it that I need to re-bleed the rear lines? I've got a new compensator and re-built rear calipers and all new flex lines.

Thanks for any suggestions.

Brian

[micbrody]

probably master cylinder is bad. not sure how it could leak out of cap, though. The reservoir has a divider, but (on mine), they are separated only half way

[hayesbd]

On the older cars, there are two separate reservoirs with hoses going to the two ports on the master cylinder. The reason it can leak out the top when one gets too full is that they are not designed to seal completely - they have to breath somewhat to account for pad wear.

Thanks,
Brian