Pontiac Repair: 2003 Pontiac Grand Am brakes, antilock brakes, pontiac grand am

Question
I have had the car 1 month.  Braking was fine then all of a sudden the brakes would go to the floor. Took it to a garage to check the lines, all are brand new.  Drivers side front tire wouldn't bleed, the flex line was collapsed.  Changed the flex and still the same problem.  One minute there is a full brake the next it is to the floor.  Not sure what it could be, thought it may be the master cylinder or brake booster but then I would have no brakes at all not just 3.

2003 Pontiac Grand Am
2.2 Ecotec

Thanks for your help!

Answer
Hi Samantha:

if this had all new brake lines on it recently chances are the brakes were not bled properly. or it has a mastercylinder issue. I'll assume this car has antilock brakes and if that is the case the anti lock brak module needs to be bled with a scan tool it cycles all the valves in the cylinder and pushes the air out down stream so it can be bled at the 4 corners of the car. The is a chance the master cylinder is bad too if the brake were bled the master cylnder is stroked more then the usual travle for a normal stop and corrosion and debris buibs up in the master cylinder and if the cylinder is moved into that area of crud in the cylinder it can damage the seal in the cylinder. Try the bleed with a diganostioc scan tool first and if that doesn't work it will need a master cylinder. good luck :-)