Brake system flush

excellent answer the only thing to clean it with any thing else can mess up the seals and orings. and by the way dot 5 and dot 4-3 dont mix if you dont believe put some together in a cup sometime just as an experament. it may suprise you how they react together.

I will reiterate one time. Flush with clean brake fluid from a sealed container. If you think that a change to DOT 4 or DOT 5 will yeild a performance gain, then I say you need to invest in upgraded hard parts. My father was a career automotive service professional and he would always preach about the importance of proper brakes. "It doesn't matter how fast you can go, unless you can get it stopped." Alcohol, brake clean, carb clean, will attack the rubber seals and lining of the brake lines, leading to degraded braking performance. If clean brake fluid won't flush out the problem, then the component needs to be rebuilt or replaced.

Too many people think that brake fluid is a permanent thing. We must remember the forces at work in a brake system. The brakes on your KZ convert forward motion (kinetic energy) into heat to stop the bike. Any heat that cannot be dissapated by the brake rotor(s) is absorbed by the brake fluid through the brake caliper(s). This heat serves to degrade the brake fluid, necessatating frequent replacement. My service manual recomends brake fluid replacement at 6000 mile intervals. KZ's are particulary hard on brake fluid b/c they are heavy, fast, and only have one solid front brake rotor on the early models. I notice the diminished performance in braking on my zx-10r at the end of a oil change interval on a 400lb bike with 310 mm cross drilled twin brake rotors with four piston calipers running DOT 4. Please understand that your brakes are the most important system on the motorcycle to have proper function.

Since you are rebuilding the calipers, air is already in the lines so no big deal there....

Here's what I did with mine...
Rebuild the calipers (clean and new seals), gaskets what ever... Use brake fluid cleaner to clean thoroughly as depicted in my ZX636 manual for calipers...

Now I installed new SS brake lines, for old, just blow them out, pump some new/clean brake fluid through them should be good to go.... Re-assemble calipers and lines.

NOTE: Use NEW banjo bolt compression washers!

Fill your reservoir with specified brake fluid and start pumping into the lines for pressure build up...

Now, here's the BEST little tool I found and the cheapest for bleeding lines, especially DUAL front disk setups... It was the only thing that worked this well for I was having one hell of a time previously getting all the air out of the lines....

Napa Auto parts, $6....