No brakes on my 2001 Yukon Denali

[melaniec1225]

My husband changed out all the brake lines on our 2001 Yukon Denali and we have bled the brakes and master cylinder. When the car is off it feels as though we have brakes bit as soon as we start the engine the pedal goes back to the floor, help!

 

[Jeff Groves]

Was the ABS module bled also?