ok i went to drive my car the other day and i had no brake pedal it went straight to the floor. checked the fluid it was out completely but didnt see where it all went i know it was fine last time i checked it a few weeks before. I put new fluid in and pumped the brakes with the car on and still got no pressure. im thinking its the master cylinder but not sure how to pin point the problem. I tried taking the lines off the master and pumping the brakes to see if it shot out any fluid but the bolts wont come out. but it sounds like the pump is moving but just pushing air like its not moving the fluid around or nothing.i checked around all the calipers and dont see no fluid leaking there at all or anywhere really. the fluid in the resevoir hasnt went down at all since ive pumped them numerous times.id just like to know if anyone thinks its the master so i can buy that and know what i need to do to bleed the whole system. i have read about the whole bleeding system that needs to be done..involving the abs unit and bench bleeding the master cylinder. as far as the abs unit goes what do i use to bleed it i seen the pics of the bleeder screws but what do i do then. what hooks up to them or whatever? any help or suggestions would be great thanks

 

It may be leaking internally on the master cylinder. Try to just start by bleeding each caliper going PR, DR, PF DF and repeat if necessary. If you still don't have brakes you need to find out where your fluid is going.

Pedal going to the floor usually means the master cylinder is leaking internally.