All 4 Brakes are locking up 2005 BMW 530i

What is your question?

First it had no brakes at all due to rusted out brake line at the rear of the car I repaired it the booster was also sucking air so I replaced with New booster and master cylinder bleed every thing out .OK now the paddle is normal brakes when you first crank the car start down the road for a test run and it starts slowing down and the brakes are locking up I can take the hose off the booster and it goes back to normal until you take off or just apply the brakes a couple times I can also brake the bleaders and it released it came up with Abs pressure sensor there is Not one on the block by the module any help would be greatly appreciated