Assuming you performed fault isolation and normal operational checks,
Check back pressure of brake system (should be under 70 PSI at each wheel, if one brake reads 10 psi or more higher, look farther) , check minimum brake pressure (should be over 1700 psi and max around 2030 and should be equal between left and right under same pedal pressure), check electrical grounds for anti-skid control valves (ensure they are tight and not corroded), check anti-skid control valve filters (if dirty, replace), check brakes for ability to return (watch pressure plate return after pressure release, should return equally), check tranducers for smooth operation and check voltage output with drill.
If you find nothing, replace parts in this order. 1. anti-skid control box. 2. anti-skid control valve. 3. transducer
Without being there and being able to look at it, this is about best I can offer. Tons of things that could cause this but most involve electrical signal between transducer/box/valve.