Shot ABS

The girlfriends '87 4 door legend has a brake fluid resevoir on the booster as normal and another resevoir on the ABS unit. The ABS one sits lower in the engine than the booster one, and I think the resevoir on the booster is gravity feeding into the lower one and overflowing it. Anyone heard of this problem? Do you have to replace the ABS unit?

The ABS system and regular brake systems are independent. An overflowing ABS Master Cylinder indicates air in the system, or perhaps a system low on fluid when it was last engaged.