I tried searching on this topic, but only came up with clutch threads....

My brakes sometimes will go to the floor while tring to stop. I have to pump them to get pressure to build. It doesn't seem to do this everytime, but atleast a few times a day. Usually after a long time of not using them. There are no leaks, fluid level is good, brake pads were changes a couple of months ago. (I didn't open the brake system, so I don't think this could be related). Nissan says that they think it is the master cylinder. Any ideas. I guess it is the cylinder or th brake booster, but don't know which to go after. Any help?

 

Bleed your brakes... sounds like you have air in your system

 

yep. try that before u replace anything..

 

worst case.. downshift and throw out an anchor lol jk


Bleed the lines

 

you might have a bad brake master cylinder

 

I ended up replacing the brake master cylinder and bled the brakes with a speed bleeder. Thats the only way to go!

 

Probably should have bled the brakes first. Sounds like you might have had moisture in your fluid which causes the fluid to boil faster than normal.

This will create the same exact scenario you were mentioning. But good to hear you got it fixed.