2005 Suzuki GSXR 600 BRAKE PROBLEM

I have this 2005 GSXR 600 with 8k miles. My front brakes lock up
when the bike gets heated up. I bleeded the brake system 2 times,
i put i the DOT 4 fluid. I cant figure out why they start tighting and
then locking up when gets heated. To fix this temporary, i release the
valve on top of the master cylinder. But then again it happens after
a while. Please give me some ideas where to start with this?

You have air pressure building up in the hydraulic system, or you have a
stuck
piston in the caliper.

There is a tiny air bleed hole in the master cylinder which allows air in the
system to rise up into the brake fluid reservoir. In master cylinders that
have
the fluid reservoir attached directly to the master cylinder, you can remove
the cap and look down into the bottom of the reservoir and see the air bleed
hole and poke a needle into the hole and clean out the crystallized brake
fluid so air can pass through it.

I don't know whether you can see the air bleed hole in a master cylinder with
a remote reservoir, the bleed hole might be in the master cylinder itself.

If the problem is caused by a stuck piston in the caliper, you might be able
to remove the caliper, remove the rubber dust seal and squirt brake cleaner
around the pistons to get rid of brake pad dust.

But, if the pistons are sticking, itcould also be caused by internal rust or
a build up of rubber dust.

I had a piston sticking on a car once. The previous owner had forced the
piston into the caliper with a screwdriver and had actually bent it just
enough to make it stick.