Assuming you don't have anti-lock brakes,

The factory manual for the 88 CRX (you can find it online) is very specific on:
-Pushrod Clearance Adjustment, page 13-25 (that the gap between the booster and the master cylinder)
-Pushrod Adjustment, page 13-24 (provides the correct pushrod length to connect the brake pedal to the booster)

It sounds like one or both of these is not adjusted correctly (which might be putting pressure on the brakes without your foot being on the brake pedal; maybe, there's some kind of positive feedback loop that makes the problem worse as you hit/release the brake pedal)

If all else fails, call your local honda dealership and talk to one of their technical assistance people.