alright....here is the deal. my buddy broke his leg so his z400 sat for about 4 months w/o moving. he started it up, but could not ride it. anyways, the rear brake seized up. so, i took it off, popped out the piston, cleaned the rear caliper up, inside and out! the piston moves freely now. so, i bleed the brakes, and i had a very spongy pedal.

my first guess, the caliper. so i get a brand new one, put it on, bleed the brakes, and still spongy pedal. i know there is no air in the line, i bled them way more than usual. I also tried to adjust the height of the brake pedal, no luck as well. what can it be? i am using dot 4 fluid, and i cant think of anything else.

 

The spongy feel. I don't know how to put this in words. Does it feel soft then get solid and then just sink all the way down when you step on the pedal? The point I'm getting at is the master cylinder has possibly gone south. They may or may not make a rebuild kit for that year. There's not that many parts involved. It's either the master cylinder, hose or caliper. I'm assuming there are no fluid leaks in the system correct?

 

i blew the line out, no leaks/ no dirt or anything. i figured that the master cylinder is the only option left, so i ordered a rebuild kit for 25.00, we will see if that helps. thanks.

 

make sure the brake fluid is new u cant use old brake fluid it absorbs water