I own a 04 g35 coupe 6mt and I am having a lot of brakes problem. On first press, my brake peddle will go to the floor without the car stopping. I have to pump the brakes before it hold. I changed the master cylinder and lines but that did not help. Please help!!!!

 

take it in to infiniti or local brake shop and have them take a look at it....

 

x2, tell them exactly what happens and that youve swapped master cylinder already and that hasnt helped.

 

You need to bleed the brakes. It sounds like you still have air in the system.