95 e350 abs control unit info needed

Hello, I did a brake job on my van. It has a new booster, new master cylinder. I bled the system. System is tight - no leaks. It's not losing fluid. The brake pedal still drifts to the floor when engine is running. Pedal holds with engine off. I'd like to have some information on the hydraulic abs control unit and/or proportining valve as I believe this is part of my problem. Thanks in advance for your help.

Hello, I did a brake job on my van. It has a new booster, new master cylinder. I bled the system. System is tight - no leaks. It's not losing fluid. The brake pedal still drifts to the floor when engine is running. Pedal holds with engine off. I'd like to have some information on the hydraulic abs control unit and/or proportining valve as I believe this is part of my problem. Thanks in advance for your help.RABS valve is leaking internally its on drivers side frame rail...