2000 r6 brake problems

[mattg]

 

My brakes have always been dragging, a lot.  I get about one revolution out of the front wheel when I spin it by hand.  I put new seals in my calipers (no tricks to that, right??), and re-bled the brakes.  I went the trackday at road america this weekend as was a little surprised when I didn't have brakes going into turn 6.  They were great into turn 5, but I had to put 3 pumps into them to get anything into 6.

I tried a new master cylinder, but it didn't help.  I'm not certain, but my lines may have been a little wet around where the stainless steel braiding meets the fittings.  Also, after I got back from a lap where this happened, my front brakes were dragging a lot, again.

I have stock 2000 R6 brakes, with goodridge S/S lines, and DP Race pads that have maybe 8-10 trackdays on them.

Any ideas?  I'm really at a loss.

[mattg]

Just wanted to add that my MC is the stock nissin, and the one i swapped in was from an 05r6, a yamaha OEM brembo MC.

[tstruyk]

any wierd feel coming through the lever?  vibration?  Is the drag intermitant or constant (does it pulse?)

thinking warped rotors...

the initial drag may be from a slightly mis-alligned axel.  re-measure your fork height but do it from the axel to the lower triple.  That may be causing SOME drag, and then if the rotors are warped, at speed it may be pushing the pistons back a hair (kinda like when you get a tank slapper) requiring you to pump to regain pressure... dunno, just kinda "thinking" out load.

I dont think its a air problem... pumping a lever with air in the line wouldnt rebuild pressure, I wouldnt think.

[mattg]

braking is perfectly smooth, no shaking, vibrations, or anything.  no headshake at all.

[tstruyk]

what happened after T6?  brakes work?  still fade throughout the day?  was this a one time instance?

[mattg]

every time I used them hard, I'd have to pump them back up.  I used two different fluids, both were supposed to be good. 

once back into the pits, they felt fine.  I could use them normally into 1, and still have fine feel into 3, but after braking for 5, I'd have to pull the lever a few times into 6.  Then again, I'd brake hard into 8 and not have much left for brakes into the chicane.

[Sobottka]

if you gotta pump em up you most likely have air... that'll make em drag too

[mattg]

really????

i've bled them a ton, I don't get any air out of the calipers.  When I was running that radial MC, I would maybe get one bubble out after a session.  but getting that bubble out wouldn't help the dragging.

I was thinking maybe a rotor is slightly warping under hard braking, and then cooling and then I need to pump the pad back to the rotor.  I did sometimes feel the brakes stiffen up towards the end of the T5 braking zone.

???

[mattg]

but then that still doesn't explain the dragging.

[wills rims]

but then that still doesn't explain the dragging.

Have you tried bleeding you brakes at the banjo bolts and all the bleeder screws. Sometime air will stay at those locations and not go past. Try the mastercylinder banjo bolt too.

[Super Dave]

I've had my R6 rotors warp like a bowl.  No pulsing at all, but eventually, the bowled out shape would push that pistons back, and my initial pull was to flatten out the rotor.  Then, nothing to slow the bike.  It was so bad once that the rotor contacted the caliper itself. 

I thought it was more of a problem with the '03/'04 rotors because they had so few floating buttons to transfer heat.

Might be worth a look.

[GSXR RACER MIKE]

Is your brake fluid reservoir full? If your reservoir is full the fluid has no place to go as it heats up and can cause braking issues. The fact that your having issues in or immediately after hard braking areas would add possibilty to this being a potential cause of your problem due to the tremendous heat just generated and not dissapated yet. You should keep the reservoir about 1/2 to 2/3 full so the fluid has a place to expand to.

Now wouldn't that be an easy fix if that was it! 8)

[Thingy]

+1 on Super Dave's idea.

[mattg]

Is your brake fluid reservoir full? If your reservoir is full the fluid has no place to go as it heats up and can cause braking issues. The fact that your having issues in or immediately after hard braking areas would add possibilty to this being a potential cause of your problem due to the tremendous heat just generated and not dissapated yet. You should keep the reservoir about 1/2 to 2/3 full so the fluid has a place to expand to.

Now wouldn't that be an easy fix if that was it! 8)

Yea, Wink told me to take some fluid out at putnam a few weeks ago.. I wish it was that simple.

I think I'm going to look for rotors, and if that doesn't fix it, new pads, then i dunno.

Do I need to replace the rotor mounting bolts when swapping bolts?  are they torque to yield? What's the torque spec?

thanks for the help guys!!

[tstruyk]

you can find torque specs in a shop manual, they have them available for download on the r6messagenet under maintanence... I believe its a sticky.  let me know if you cant find it I can get you there.  I'll be at RA all weekend so it may be monday...

good luck!

Tim

[Team_Serpent]

1. Brake drag:

That model R6 has always been notorious for front brake drag.  I spent hours getting that system to work halfway decent.  If your willing to spend the time, here are some things you can do.

First take the pistons out and polish them.

When you re-install, use permitex caliper piston grease in the grove of the seal and spread on the piston face as well.

After you've got everthing back together leave the calipers off and work the pistons back and forth (this is easier with the pads installed, make sure to put something in-between the pads of the caliper you are NOT working on to keep the pistons from popping all the way out) by pumping them out with the lever and then pushing them back in.  After a while you should start to see them retract when you release the lever, now your brake drag should be minimal.

remove the pads and wipe off any excess piston grease to avoid attracting dust/dirt.

In the future - Do not use brake cleaner to clean the calipers and pistons as it dries out the seals.  Use something like WD-40 or some guys like simple green.


Bleeding the system:

Sounds like you have air some where and/or probably need new pads.  Like someone said above try bleeding at the banjo bolts but tip the caliper so that the banjo bolt is facing up.  Sometimes a stubborn air pocket will be in the top of the caliper cavity and it will come out if you bleed from the banjo with it facing up.  You could also try putting a rubberband around the lever and handle bar over night, this will sometimes get stubborn air bubbles up to the MC reservoir. Repeat, repeat, repeat.

Pads:

You probably need to replace.

Rotor bolts:

Can't remember if these are torx type or allen but the best way I've found to remove either is an impact driver (the kind you hit with a hammer) otherwise you will most likely round the head of a few (which turns your project into a nightmare). I have had to use heat on some in the past as yamaha uses a ton of locktite.  They are torqued to a very low spec, something like 13 lbs. if I remember correctly but a real bitch to get out the first time.  I have not used locktite on re-install and have never had a problem.

Warped rotors:

Maybe, but I'd work on the other stuff first (bleeding and pads) they are cheaper.


Hope this helps, feel free to pm for my number if you have questions or need more detail.

[dylanfan53]

I'm gonna butt in with a quick question...

When you use heat should it be applied directly to the bolts or to the wheel around the bolt?  I keep getting different answers. Thanks.

[Team_Serpent]

I'm gonna butt in with a quick question...

When you use heat should it be applied directly to the bolts or to the wheel around the bolt?  I keep getting different answers. Thanks.

Those bolts are really soft to begin with, I used a propane torch (home depot has them cheap) and heated the area of the wheel around the bolt being careful not to over heat and damage the finish.  It really didn't take much heat, just enough to soften the locktite.

You may not even need it if you use the impact driver (highly recommended).  I don't even try to loosen rotor bolts that have never been removed before without an impact driver.  It just makes the job so easy and pain free.

I also take a sharpie and make a mark on the bolt head so I could see if the impact driver moved it.  Sometimes the bolt moves so quickly when you hit the driver you can't see it move without a mark.

Here is a link to an example of the impact driver I am reffering to http://www.kk.org/cooltools/archives/000723.php

[Team_Serpent]

Another tip on reducing brake drag is how you pump up the brakes after install or wheel changes.  Only pull the lever halfway multiple times to bring the pads out to meet the rotors rather than making a couple of full strokes.  The pressure that builds in the MC when you pull the lever a full stroke will effect the amount of retract of the piston when the lever is released.

[dylanfan53]

Good stuff. Thanks. 

[tzracer]

I prefer using a heat gun rather than a torch. A good deal of the flame from a propane torch is not very easy to see, it is easy to accidentally heat/burn another part or start a fire.

Remember you are only heating enough to soften the thread lock, probably not even 200F. Some heat guns have temperature control, I start at about 150F and that is usually enough. I also have a tip for the gun that concentrates the hot air through a tip about 1/4" in diameter.

I also heat the bolt, shortest path to the thread locker. This also reduces the chances of damaging other parts due to heat - example - wheel bearings do not like heat, heating the hub can over heat wheel bearings. Also aluminum requires more heat to warm than does steel (specific heat of aluminum is twice that of steel).

[Team_Serpent]

I prefer using a heat gun rather than a torch. A good deal of the flame from a propane torch is not very easy to see, it is easy to accidentally heat/burn another part or start a fire.

Remember you are only heating enough to soften the thread lock, probably not even 200F. Some heat guns have temperature control, I start at about 150F and that is usually enough. I also have a tip for the gun that concentrates the hot air through a tip about 1/4" in diameter.

I also heat the bolt, shortest path to the thread locker. This also reduces the chances of damaging other parts due to heat - example - wheel bearings do not like heat, heating the hub can over heat wheel bearings. Also aluminum requires more heat to warm than does steel (specific heat of aluminum is twice that of steel).

Never thought about using a heat gun, I recently got one and will try your method next time, thanks!

[Kelly Ruby]

my gsxr started having tons of brake drag at moroso - i couldn't get the front tire to spin a whole revolution.  they've dragged before, but this was enough to slow me down!

i replaced the pads and that solved the problem.  apparently the metal backing can warp and that causes the dragging.  you would think the pad material would get worn down flat and it wouldn't matter, but that was not the case.

i ended up with the new "race" ebc "laser cut" pads - supposed to cut down on warping since they are laser cut and not heat cut so they don't lose their tempering.  downside is they are only available from trackside vendors at $80 a set (for me).

[mattg]

Well, I replaced the rotors and one of them was dished.  but I'm still getting brake drag.

I've cleaned my pistons.. they aren't pitted or dirty at all.. but I didn't polish them.  I just used paper towel and brake cleaner, dried them and reinstalled. 

I'm going to get new pads, and I guess I'll do the pistons again when they come in and get them really clean with a scotch bright pad.  I'll also try working them in and out.  guess that's all I can do :(

[Team_Serpent]

I've cleaned my pistons.. they aren't pitted or dirty at all.. but I didn't polish them.  I just used paper towel and brake cleaner, dried them and reinstalled. 

I'm going to get new pads, and I guess I'll do the pistons again when they come in and get them really clean with a scotch bright pad.  I'll also try working them in and out.  guess that's all I can do :(

Did you use the piston grease I recommended before installing?

I would NOT recommend using scotch brite on the pistons, to polish simply use a metal polish like Semi-chrome or Mothers then, re-read my posts in detail and USE THE PISTON GREASE!

[mattg]

when I last had them out, I did reinstall using piston grease.

i'm going to work on them tonight or saturday and see where i end up. I'm going to try to work the pistons in and out to loosen them up.  Only 2 move in and out on each caliper when i pump them.. that's gotta be the cause.  i hope.

[Team_Serpent]

when I last had them out, I did reinstall using piston grease.

i'm going to work on them tonight or saturday and see where i end up. I'm going to try to work the pistons in and out to loosen them up.  Only 2 move in and out on each caliper when i pump them.. that's gotta be the cause.  i hope.

Sounds good, I had to work them in and out quite a bit to get them to all start retracting properly.

Even after all the work I put into that system I could never totally get rid of all the brake drag and I was always going back over things to keep the drag minimal.

I'm not sure what it is about that system but the later models are much better.

[DanO966]

haha brake drag on a first gen R6...lol

Jason's ideas work very good but the main ? is what pads are you using?  the backing plates warp which cause a lot of the drag...
On my first Gen R6 I ran Performance Friction 95s and that seemed to minimize the drag.....
good luck

[mattg]

I have DP Race pads in there now.. They're barely worn.  I'll check the backing plates this weekend to see if they're warped at all, but I'm guessing if they are warping, it's only after they're heated.

I also found on the wera board some people talking about the brake lever causing it.  I realized that when I put my lever on, it compresses the piston a little bit.  I took the lever off, and ground down the side of the lever by the brake light switch (brake lights??) to keep pressure off of the master cylinder piston. 

I'll report back in a few days :)

Thanks for the help!

[mattg]

they're still dragging.  I get one revolution out of the front wheel.   

I let someone fast ride the bike and his only comment was "the brake lever is nice and firm"....  It is, until about 7-8 laps when it fades. 

I did get the pistons on the calipers to move freely.  I can see them retract a bit when I release the lever.  Vesrah RJL's are on the way.

[Team_Serpent]

What about the front brake lever prob you mentioned?  Did grinding a little away help any?  Keep working at it but don't get all hung up on it, I think the best I ever got on that bike was three revolutions of the front wheel. 

Sorry, first I read about a fade problem after 7-8 laps (must have missed it in you earlier post).  Not sure whats going on there.

[resurection]

Ive seen seals in the master brake up and lodge and dislodge into the rel if hole maybe this explains the sticking and extra pump after dislodging