Zx6r Brakes build pressure over night.

[JBZ1k]

Ok, I'm working out of town and when I get home I'll only have three days to slam my bike back together before road Atlanta and I may have an issue so I want some ideas before I get home.

So...everybody knows if your front wheel is off and you show a relative your bike the only logical thing for them to do is squeeze the brake lever right?

So I put the wheel on, look at the calipers and make sure none of the pistons are out, remove the fill cap, and proceed to try and wedge some screwdrivers in between some old pads to push the pistons back to a width to allow for instillation. Easier said than done, normally this is easy but the only way they would go back in was if I bleed the fluid off.

All back together, pump them up, not worried about bleeding them because when I got the new pads I was going to change the fluid, let it set over night and the next day I go to move the bike and the wheel is locked up....scratch my head...wtf... So I feel the lever and it is rock hard. I let some pressure off the bleed screw on the caliper and its all good.

Now this has happened every day since I put it back together.

My plan is to loosen everything up, recess the pistons, replace the pads, replace the fluid, bleed the system and hope it's all good.

But if its not I want some ideas about what else to check.

Btw the bike is an 2010 zx6r, 2,200 miles, fluid was a little less than half up on the canister.
Thanks!

 

[blueninja1]

Sounds like there is dirt in the system or too much fluid. Perhaps air is being trapped somewhere in the line. All the scenarios I can think of. Good luck.

 

[JBZ1k]

It may be dirt but it definitely is not over full. I hope it's air as that would be an easy fix.

My thought process tells me that even if it were air something in the master would have to let the fluid return to the reservoir... I just don't want to slow for 10 at road Atlanta and find myself parked in the middle of the track...might have to safety wire a wrench to the clipons so I can bleed it off after every corner lol...

 

[blueninja1]

I had a similar problem with my dirtbike. Sometimes the lever would work okay, but on the next pull it would get all stiff and solid like something was jammed in there, and kind of stay that way throughout the day. I kind of got away with riding the bike that way since in the dirt you actually depend on the rear brake more than the front.

If it was me I would take the whole system apart (including the caliper), inspect for worn out parts, etc, replace what is needed, and put it back together. It would take a bit of time but will save you the headache of wondering what if the brakes don't work after this long straight. Or if you don't have the time you can try and get a reputable shop to handle it. If you handle it yourself it helps to have a brake bleeding kit like this to make the process much faster: http://www.motosport.com/dirtbike/product/?pssource=true&psreferrer=http%253A%252F%252Fwww.google.com%252Faclk%253Fsa%253Dl%2526ai%253DClApZ60FTUYfIC6776QHasICQC9mvx4QDoZXPqUeZv5CRsgEIBRACKAVQ79iYxgdgycapi8Ck2A-gAZGitP0DyAEHqgQnT9BNxNB8-Mc9eouzLxOuyjVa7CnANsQSTsxmNdM3xxFcVls9NA59wAUFoAYmgAfX3csC4BK0q-3SrZDMwCo%2526sig%253DAOD64_2-uj2Uwrnbk2stPD9tNWS1aeaSPg%2526ctype%253D5%2526ved%253D0CDUQww8%2526adurl%253Dhttp%253A%252F%252Fwww.rkdms.com%252Fredirect%25253Fc%25253D807144684%252526en%25253D27%252526cl%25253D500%252526u%25253Dhttp%2525253A%2525252F%2525252Fwww.motosport.com%2525252Fad%2525252F%2525253Fcode%2525253DSS-D-G-PRODUCT-EXTENSIONS%25252526key%2525253DMITYVAC-MV8000-BRAKE-BLEEDING-KIT%25252526utm_medium%2525253Dcpc%252526kw%25253D%25257Bkeyword%25257D%2526rct%253Dj%2526q%253Dvacuum%252Bbleed%252Bmotorcycle%252Bbrakes&key=MITYVAC-MV8000-BRAKE-BLEEDING-KIT&utm_medium=cpc&gclid=CKC6-8jKnbYCFQyg4AodwycA1Q&segment=badger. Use brand new dot4 fluid and you should be good to go.

Check every little part meticulously. Maybe the reservoir bladder is screwed up somehow. Maybe it might be worth getting a whole new system if you have the coin? That would surely cover all your bases.

 

[zenpixel@yahoo.com]

"the only way they would go back in was if I bleed the fluid off."

something is very wrong with this scenario. the fluid should move freely back up the lines when you push the pistons apart.
I'd go with the PITA of tearing it ALL down and then rebuild. safety first.

 

[JBZ1k]

I'm going to start by running some fluid thru the system then take the master apart and clean everything good.

The system has been kept very clean its whole life as I change fluid every 4 TDs.

Ill let everyone know what I find when I get back in town.

 

[Otto Man]

I'm a man of simplicity, and would take things step by step to see where it's hanging. First thing I would do is disconnect the calipers from the lines and see if you can push the cups back that way. If you can, then you know your problem is in the lines, or the mc. I highly highly doubt your calipers are dirty being only 3 years old and 2k miles. If i had to guess, I'd say the mc piston is still stuck in from the relative squeezing the brake lever. With the calipers off, nothing to push it back.

I retract my first statement... First thing I'd try is bleeding at the mc and see what happens. If that doesn't work (caliper pistons/cups still won't retract), then I'd disconnect the calipers, in an effort to narrow the problem.

 

[blueninja1]

Sometimes it helps to have one or two buddies around who have experience with such repairs. They may see a problem that you aren't necessarily looking for. I know having an experienced friend around has saved me a lot of time and stress many times whenever tearing bikes apart.

It's not a luxury you may have all the time but if you have the chance, snatch it up. I kind of agree with Otto that you CAN sort of start testing one part at a time to try and get to the source. Start from the outside and work your way in. Usually you will find the part that is not working smoothly. That is the most important thing, to make sure everything moves/engages smoothly. You will find the problem, eventually. Just a matter of time.

Look at every nook and cranny, how the lever bolt comes into contact with MC point of contact, inspect inside the reservoir, push the caliper pistons in and push them out by pumping the lever. If all checks out flush the lines to see if there is any dirt, etc.

Maybe you can snap some pics during your venture so we can inspect too. I kind of like getting into the nitty gritty, although it does take a bit of work. An afternoon working on the bike is a good afternoon, right?

 

[Lonewrench]

Let me know if you need help

 

[JBZ1k]

Thanks Chuck.
One thing I have changed since this started was the levers.
After reading more I found some cheaper levers are not made very well and can be machined incorrectly causing the plunger on the master not to return to a fully open position making it hard or impossible for the fluid to return to the reservoir.
I didn't exactly buy cheap levers but that's the first thing coming off Tuesday night when I get home. If the brakes release when I do that, problem solved.
After everything I saw on the net about levers I don't think I'm going to run aftermarket.

 

[HondaGalToo]

Aha, levers. I've also heard of that with the cheaper knock-off brands. If you go aftermarket CRG or Pazzo work fine, I've used both. Heard good things about ASV too.

 

[Lonewrench]

BTW the problem is the levers I just wanted to see if someone was going to pipe up,glad they did. Bottom line is ,there is little to no room between the M/C piston and the plunger on the new lever. a slight mod and you will be good to go.