My car E200 1991 have problem suddenly "free brake" during driving in the street. I check brake fluid and found empty fluid and I check brake fluid hose. Found that fluid leakage on seal disk brake right back whell. After changed fluid seal disk brake, I top up brake fuild and pump fluid with press repeately brake pedal. But after several times still "free brake" and fluid not flow to the brake disk. I check fluid flow after brake master and fluid flow with high pressure through ABS system. But after ABS system fluid not flow.

Whether ABS system is destroyed ?
How to solve the "free brake" problem ?

Thank & reagards,