I have a 2003 Suburban that a week ago rusted through the rear brake line. I replaced the lines and bled the system. The brake light is still on and the service brake system is still on in the DIC. My pedal isnt there at all. If i pump it up quickly when off I will get a good stiff pedal, as soon as I start the engine it goes straight to the floor. My local mechanic helped me to replace the master cylinder after we checked all of the joints and other lines to make sure they were't leaking. I still after installing the master cylinder have no brakes. It just goes straight to the floor and the warning lights are on. If anyone can help I'd appreciate it. I really need this vehicle back on the road. Thank You!

 

Sounds to me like you may have air in the abs pump or your master was not bled correctly prior to install. If you know for sure the master was bled correclty see if your mechanic friend is willing to help you again and he has a bi-directional scanner ask him to go into the scanner and command the abs pump to come and to help bleed the system. You will still have to open the bleeders of course. Otherwise youll have to just keep bleeding the old fashioned way. Also it is a good idea to always start at the right rear then left rear, right front and finally left front.

-best of luck
brian