I have a 1998 blazer, and I am having issues with the brake system. When I press on the brakes it goes to the floor, but it still stops the blazer. It is not leaking any fuild and the MC is full. I already make sure that no air is in the lines. My question is this, do I need to replace my MC or the booster?

 

are you sure the master is full, look closely it is separated into a front and rear section, the rear may be empty... is the "brake" light on?

just saw the no air in lines note

 

Yes the brake light is on

 

more then likely a leak in the rear circuit, probably empty in the back of the resevoir

 

The MC is full even the back resevoir

 

there is a leak some place or the M/C is shot

pump the pedal several times and see if it builds up and then look for a leak

 

my money is on a bad master cylinder....