I have a ultima custom kit bike I'm the second owner the problem is the brakes are spongy front and back the guy that built this bike said that they have always been this way. I have bleed them power bleed them with no improvement I don't know what to do concidering a rebuild kit for the master cylinders

 

If it's not air in the lines it could be old brake fluid, moisture in the fluid or the wrong grade fluid. Have you tried flushing and cleaning out the system with denatured alcohol? Or worst case senario, the master cylinder bores could be the wrong size for the calipers. Who knows what companies throw in those bike-in-box kits or what changes people make during assembly.

 

thanks I think I'll try the rebuild kit seems to be the cheap way to go

 

You don't say what year your bike is or how many miles. Your brake lines could also be soft if they're original.

 

there's no speedo but I think there's only about 3000 miles

 

last night I took the calipers off and was checking it . what I found out was this bike has a 4 piston brakes I pull the brake leaver and only 2 of the pistons on the outside was working.

 

Your pistons are sticking in the caliper. This same thing happens on the HD calipers. You take apart the caliper, remove the pistons and clean the hell out of everything. That's what made my 04 Ultra brakes like new.

Don't waste your time with the master cylinder rebuild.

 

I found out that the 4 piston calipers was too much I put on a single piston and I have great brakes now

 

if you go back to multi-piston, and assuming the proper master for the application, try bleeding it from bottom up. use large syringe, push brake fluid up lines to master from calipers. then squish out final bit of air from the master by working the lever a little bit. this gets all the air out especially on dual front multi-piston brakes. when doing dual front brakes, push about 30cc of fluid up the right side caliper line first, then do left side, push fluid up line until it fills master. good luck.