what causes two lines too bleed but not other 2 vice versa front an back?

Question

left front catches and right rear catches and pedal goes too floor and bleed for 2hrs or more

Answer 1

the rubber lines to the wheels can get old and restricked, do you have a duel master cyclinder? :)

they may have debris blocking the bleeder valve

You need to get a 1 man bleeder kit from the parts store

Answer 2

Maybe you don't really understand how to bleed your brakes! Usually you need 2 people, one to pump and hold the pedal, and one underneath to turn the bleed valve. It's not unusual for the rear brakes to take longer to bleed, the lines are longer. Also consider you may have a problem with your master cylinder.