[w1ck3d zx6r]

Ok so here is the problem.....

I have installed the 07 Nissin Calipers and the Core Moto SS Lines on my 2006 ZX6R 636 as well as my brothers bike (same model same year). Both bikes have the Nissin M/C as well. Everything went great with my bike and works as it should. Awesome pressure at the lever which in turn provides great braking. As for my brothers bike it has not gone so well. It has taken forever to get pressure back in the lever after bleeding the brakes. When we finally did we went for a ride his front brakes were progressively getting tighter and tighter until he could no longer pull the brake lever and the calipers were pretty much locked up. I cracked the bleeder valve open to relieve some pressure and that released the brakes so we could ride back home with him just using the rear brake. Once home I had taken the front calipers apart to see if anything was hanging them up but they surprisingly looked practically brand new inside. the pots/pistons were very smooth and the seals were in great shape. I cleaned everything up anyway, lubed everything up and put everything back together and re-bled the brakes. It took the same amount of effort as before to get pressure back but once we did we went for another ride. the same thing happened. This time I relieved pressure from the bleeder at the M/C and the brakes released once again which leads me to believe that the M/C is not releasing the pressure back into the reservoir, which by the way is not over filled.

I have been searching the inter-web for the past couple hours and still can not find the right solution for the problem with my brothers front brakes. I have also been trying to locate the correct rebuild kit for the M/C but with no luck on that either. I am almost positive that the calipers are not the problem and that it is indeed a problem with the M/C. Any light shed on this matter would be greatly appreciated whether it be a possibly solution to this problem or a direction to the correct rebuild kit. I know there are a lot of great minds on this forum and I am looking forward to hearing your thoughts. We are so eager to get out and ride together so the sooner I get this resolved the better. Thanks in advance! Sorry for the book :laugh

 

[RJ2112]

Are the rotors true? Check the runout on his rotors. Elevate the wheel and spin it. Does it stop sooner than yours?

 

[NatBrown]

You have installed the front brake lever incorrectly. The pin in the M/C has to go into the hole in the rotating barrel in the lever. Any misalignment will cause the locking up over time of the front brake you are describing. Take the lever off, make sure the barrel part is rotating freely and then reinstall it making sure the pin is correctly aligned and everything is working freely.

The lack of pressure and problems bleeding the system is most likely a worn out M/C that needs to be rebuilt. That would be the first thing I would try if i was confident in my bleeding procedure.

 

[Ebster1085]

You have installed the front brake lever incorrectly. The pin in the M/C has to go into the hole in the rotating barrel in the lever. Any misalignment will cause the locking up over time of the front brake you are describing.

This could very well be what you are experiencing.

You say you are both using a Nissin MC, but is it the 05/06 unit or did you also both upgrade to the 07+ model?

 

[w1ck3d zx6r]

Problem Solved!!

I took everyone's advice and checked the rotors then the master cylinder (it is the nissin M/C for the 05-06) and finally the lever itself. Everything looked to be as it should so I swapped my brake lever onto my brothers bike and the brakes did not lock up plus the pressure of the lever was exactly like mine then. So I decided to put his lever on my bike and what do you know my brakes started locking up. I put both levers side by side (both levers are stock levers) and I could not really see anything that was different until I held both levers long ways up and down. I noticed something was bent in about 1/16"-1/8". If you look at the picture below I circled what was bent in....(not actual lever pictured but a lever for the 06 zx6r just for demonstration purposes)



So with that being bent, it angled the lever in some so it was pushing in on the plunger on the M/C slightly and dragging the brakes and when the system built up pressure and the fluid heated up the pressure couldn't release back into the M/C and reservoir causing the brakes to lock up. So I held the lever over a piece of 2x4 and hit it a few times with a dead blow to bend it back to where it should be. Put everything back together and went for a 2 hour ride and the breaks performed like they should. Thank you everyone that put the advice out there. I probably would have never thought it was the lever :coocoo but hey you learn something new everyday right? Ride safe everyone!!