How do I separate the brake master cylinder from the boost chamber? Brake pedal went right to floor, checked for line leakage & caliper & drum pistons & external master cylinder...no leaks! Added 500ml of fluid in total to brake reservoir & each time I tried the brakes the fluid would go somewhere but again no obvious leaks externally. Suspect brake master cylinder is leaking into the vacuum boost area. Disconnected the 4 brake lines & the reservoir line & the 2 mounting nuts from the master brake cylinder but can not remove the cylinder from the boost chamber? Is something else holding the cylinder onto the boost chamber?