I bled all my brake lines and the brake pedal still goes to the floor. The brakes do work but no that well at all. Also when at idle my car idels at about 800 and drops to about 200 like its loosing vaccum and repeats this. Could I have a leak in my master cylinder what about my booster?

 

HELP

 

do you have drums in the rear...are they adjusted properly? If you have rear shoes out of adjustment your pedal will go to the floor like you have air in the system