a few days ago my brakes started acting up on me. when i first apply pressure to the pedal it sinks to the floor and only the drivers side caliper engadges. if i pump the brakes, the pressure builds and both brakes work fine but they lose pressure very quickly. ive checked the calipers and both seem to be in working order and ive also bleed the brake lines to make sure there was no air. fluid doesn't seem to be leaking from anywhere, i dont see any spots on the ground. any ideas on what this could be? if its the master cylinder, how difficult is that to replace?

any help would be awesome.
thanks guys...

 

i think it could be the master cylinder, i had the same probleom on my van. it's called like sponge pedal haha. but i'm not sure how hard it is to fix, i'm guessing moderatly difficult, not to hard but might encounter other issues.

 

Do you have ABS if you do it the ABS system

 

The primary and possibly secondary cup seal in your master cylinder is leaking internally. When the seal leaks it bypasses fluid inside your cylinder, that's why you have no leaks. You'll have to replace the master cyl.

 

thanks guys. replaced the master cylinder and everything is back to normal. thanks for the help.