I am new to the forum but I am having serious brake problems I have a 2000 elantra. I am having serious brake problems. When car is off the brakes pump up & hold but as soon as I crank it they go to floor. I have already rebuilt calipers, new pads new rotors new master cylinder. Any ideas
Thanks

 

Sounds like the brake lines were not bled correctly. Possibly the master cylinder wasn't bench bled correctly either.