Nissan Repair: 2002 Nissan XTerra brake pedal, nissan xterra, master cylinder

Question
I was at a stop light the other day when my brake pedal suddenly went to the floor.  The vehicle still stops, but I need to press the pedal all the way down in order to do so.  Is this a master cylinder issue, air in the line, broken line, etc?  I've checled the fluid level, and everything is fine.

Answer
Hi Chris -

You have a defective master cylinder. Inside your master, you have a variety of oring seal, and looks like one of them is leaking within the cylinder. This is why you do not have loss of level for the brake fluid.

Replace the master, and you should be good to go -

Hope this helps Chris -
aloha
calvin