Front rotor chattering

[bajabomber87]

My front brakes have been iffy now for awhile, front brake lever goes soft, then hard, and the pads went bad in about 2k miles, originals lasted 15k!

Took it to Harley, they kept it for a week and all that happened was the pistons were removed and greased up as they told me, Ive never been inside a Buell 6 piston caliper so I dont know whats true or not. They also replaced the pads, all under warranty.


Harley says Buell is dragging their knees in getting me a new front MC (2 weeks, no answer) so I decided to just bleed the brakes myself. There was a ton of air in it and the resi seemed slightly low so I filled it up too.

Took it out for Moto GP weekend and got a ton of riding in on it, the brakes will keep pressure and feel really good while I'm out beating it on the hills and corners. But when I'm riding it on the highway or in town, it loses pressure and I can pull the lever all the way into the bars. I have the adjustment on 2, then when I switch it to 1, it just gets too touchy whenever the pressure builds up when I'm out beating it.

Talked to my service guy today and he's just going to get Buell to reimburse them so they can purchase me this aftermarket MC http://www.americansportbike.com/shoponline/ccp0-prodshow/16106.html

While I wait for that, I still have my problem of the front brakes chattering. It seems that the front rotor is a "floating" disk correct? because the rotor can move a good amount in between the mounting bolts on the wheel. Now when I grab the brakes hard, the front brakes will chatter really loud and I get a feeling that they are warped....Am I right?

Will a new rotor fix this? Also what is your take on the MC problems?

 

[keisersozae]

I had some issues with the front brake pulsating and my rotor was replaced under warranty.

The dealer said that some of the rotors were stored incorrectly prior to being installed new on the bikes.

 

[NOMORE4s4ME]

If I had that problem w my bike I would not be riding my bike AT ALL before it was fixed. That sounds extremely dangerous. Be careful

 

[bajabomber87]

Havent died in the past few months so there's not much to worry about.

I doubt they'd warranty a front rotor that is going to turn 19.5k miles when 18k was perfect, But I'll try that after they replace the MC.

 

[RT Performance]

Ok what i been finding.
Note i been bending wrenches on cars for 15+ years.
The chattering or pulsating may be pushing the cailper pistons back and why you have no brake but if you grab it twice or three times there is plenty of bite.
It seems alot of guy through a set pads on and the pulsating goes away.
I think this is due to build up on the rotor around the vent holes.
I bought a set of factory pads when i read most pulsating goes away with pads replacment.
But my current pads aren't spent yet so i took my small DA sander and sanded the outside and then hand scuffed the inside.
90% of my pulsating dissapeard.
So soon as these pads are close to being done i plan to pull the rotor and sand both sides when i put pads in.
I also seen somone mentioned that this build up is caused by ubrupt stop like at a light then sitting there with the font brake on the hot rotor makes some matrial stick to the rotor

 

[bajabomber87]

I feel kinda iffy about resurfacing such a thin rotor. seems like I'd get more warp'age than before.

 

[RT Performance]

it not a machine resurface like a car.
just deglazing like the hone or a good flat sander

 

[keppi]

You lost Brake pressure?
...how old is the Brakefluid?
Are u sure...not loosing any fluid?
Bleed the Brake correct...ore change the fluid.

 

[bajabomber87]

I dont lose all the pressure, it just softens up sometimes, to me it seems the MC piston is experiencing blow by.

It is not losing fluid that I can tell and I bled the crap out of it. Fluid is basically new when I bled it.

 

[m2guy]

Hi there,
I race a XB12r and encoutered the same problem.
The monunting spacers/washers are designed to ware away with use. Your best bet is to change the brake fluid, and to replace the rotor with a front brake rotor kit, which will include all hardware along with a new rotor. When racing we tend to go through parts alittle faster than normal. Brake fluid is always a good thing to change every year or two no matter what. Good luck!

 

[Stormn712]

I have a brake chatter as well and tried what RT Performance said. I removed the frnt rotor and sanded with a med/light emmery paper wth my palm sander (both sides of rotor). Scuffed the almost new pads, and removed all the rotor floating springs, cleaned the wholes, and lightly lubed the springs.
I still have chatter ! And the rotor is dotted with equally spaced high/hot spots. I'm thinkin my rotor z fubar ? What do you guys think ?

 

[konarider94]

I'm thinkin my rotor z fubar ? What do you guys think ?

good chance of it. order a new one from erikbuellracing.com . they are $125, you can try coupon code brake rotor. if it still works it will be 99 for the rotor. i would suggest the new style mounting hardware he uses too($41).

 

[Stormn712]

I could kiss ya konarider94..good thing I live sooo far. Where do you find the coupon ?

 

[konarider94]

i just tried to use it on their site, it doesnt seem to work anymore. it was a really old code but it did work early this spring. $125 still isnt that bad for a new rotor.

 

[rrh481]

I have a brand new master cylinder sitting in my garage if needed

 

[Stormn712]

Thanks for the offer of the master cyl rrh481. But mine z rock solid. I ordered the new rotor and fastener hardware from EBR as per Konarider suggestion. Does any one know from whom I should order reasonably priced pads ? EBR pads are pricey,
thanks

 

[konarider94]

i found some lyndall golds on ebay when i did mine. people seem to like the ebc too.

check out http://www.americansportbike.com/shoponline/ccp0-prodshow/9059.html good description of pads available but sometimes there prices are a little steep for me. great company and service though, ive used them in the past for things.

 

[jimijeans]

Baja,try this when you can,Bleed the front Brakes till it's clear.Once the brakes are done in this area Pump them up to see how tight they feel.You can also pull the lever slightly Tight and tie it off for a couple of hours.Then take it out for a GENTLE ride and press the front brakes gently then firmly, IN a straight line. I'm assuming that the pads are in the slots perfectly and in great condition.Is the Front Brakes Pulsing when you apply pressure only?Check the rotor out the small springs and drive bushings behind the rotor may need attention.Check the bearings as well.*Jimi

 

[Stormn712]

I purchased the EBR rotor with hardware as per my fellow Buelly suggested. Thanks copious ! EBR was super fast, Super Pro and very reasonable with the pricing ![up] Just finished installing the new setup according to their instructions (you no longer use the compressions springs)! I will let you guys know how it goes shortly.

 

[bajabomber87]

I already fixed the problem years ago. The stock mastercylinder was leaking internally so they gave me the upgrade and I've never had the problem since.