Ducati Monster Forum

Moto Board => Tech => Topic started by: The ModFather on April 18, 2012, 08:53:38 PM

Title: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 18, 2012, 08:53:38 PM
When I spin the front tire with the front up on fork stands I only get about 1.5 rotations. I can hear the brake drag as a small hiss as it spins. Not sure if thats normal. If I remove the right side caliper I get about 3+ spins but when I put it back on the brake drag comes back. Any ideas? Not sure if I should be riding it while its like this.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Speeddog on April 18, 2012, 09:56:23 PM
Year and model of Monster would help.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 19, 2012, 05:35:05 AM
2005 620
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: zooom on April 19, 2012, 09:48:50 AM
back up a step or few...what did you have the fron wheel off for in the 1st place?
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: scooterd145 on April 19, 2012, 12:13:44 PM
He did a tire change. Duck Off, put that thing back together, put it on the groud pull the brake lever a few times to pump the brakes up and ride it. Come back in and put it on the stand and see what it does. I bet it just needs to work a bit. The brakes are hydrolic, with nothing to push the pads back in but friction.

Question, did you do the rotate the wheel test before you took it apart? You could be comparing these results to a not know result...
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Slide Panda on April 19, 2012, 12:27:35 PM
Have you got everything in the wheel lined up right? Did you take it off the stand and, with the pinch bolts loose, pump the forks a few times (make sure you're not holding the brake lever)?

But to me, this doesn't sound off. Once the bikes been used - the pads lightly skim the rotor at all times - there's always a tiny bit of drag. I don't get any 3+ rotations of my front wheel from a hand spin with the calipers mounted and the system pumped to the point where it would stop the bike.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: zooom on April 19, 2012, 12:30:30 PM
I asked what I did to make sure nothing else was messed with before saying what you guys pretty much did....
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 19, 2012, 01:04:28 PM
Rode it like that to work. Havent been back home to check the brake drag on the stand yet on the front tire but the rear brake is my real problem. It feels almost gone now very little stopping power and I have to push all the way down. When I got to work I looked at the rear rotor and its completely scraped up. I did have a hell of a time sliding the rear rotor into the rear brake pads when remounting the tire. I wonder if I messed up the pads or if part of the shoe is rubbing against the rotor. Looks like that rotor would need to be refinished or replaced. Not sure what thats going to cost. Not good.  [bang] Any advice here?
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: take risks on April 20, 2012, 08:31:50 PM
pictures.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: manwithgun on April 21, 2012, 10:38:20 AM
Quote from: Duck Off on April 18, 2012, 08:53:38 PM
When I spin the front tire with the front up on fork stands I only get about 1.5 rotations. I can hear the brake drag as a small hiss as it spins. Not sure if that's normal.

Not quite sure what brakes you're equipped with but I'll go out on a limb and guess 2-pot Brembos?  It's been my experience that excessive drag is inherent to the 2-pot design where the pistons apply pressure to the outer pad which then relies on the caliper to slide, center, and then transfer pressure to the inner pad.  When you release the lever and the outer pistons retract slightly,  the inner pad has merely had the pressure relieved and the inefficiency of the slider causes the drag.  your experience may vary.

Also,  I like to retract the pad/piston slightly with a large flat blade screwdriver before installing the caliper to insure centering.  Just make sure that you pump yer brakes, seat the pads, and have good lever pressure BEFORE you blast down the road...
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 23, 2012, 03:05:54 PM
Well I figured out what cause the rear rotor to get scraped up like that. Pics provided. It looks like the caliper mount was actually rubbing against the rotor. Specifically if you look at the pics the it was the circle to the right of the word Brembo that was scraping my rotor.

(http://farm9.staticflickr.com/8016/7107588939_36ec59e012.jpg) (http://www.flickr.com/photos/65036619@N04/7107588939/)
IMG_5082 (http://www.flickr.com/photos/65036619@N04/7107588939/#) by ricknieto (http://www.flickr.com/people/65036619@N04/), on Flickr


I also have a close up of it here.
(http://farm8.staticflickr.com/7249/6961521158_781e0cb12c.jpg) (http://www.flickr.com/photos/65036619@N04/6961521158/)
IMG_5086 (http://www.flickr.com/photos/65036619@N04/6961521158/#) by ricknieto (http://www.flickr.com/people/65036619@N04/), on Flickr

Not sure why this would happen.  Not sure if maybe my rear wheel alignment was off and it was tilted to the right or if the pad was pushed back or what. Any thoughts on why this would happen? Heres a view from behind. You can see the pads and the silver is the piece that was scraping.  :-X

(http://farm8.staticflickr.com/7227/7107589311_19519cfcd2.jpg) (http://www.flickr.com/photos/65036619@N04/7107589311/)
IMG_5089 (http://www.flickr.com/photos/65036619@N04/7107589311/#) by ricknieto (http://www.flickr.com/people/65036619@N04/), on Flickr


Finally here is my sorry ass rotor now.  :-\

(http://farm9.staticflickr.com/8026/6961520800_b799bfc2b0.jpg) (http://www.flickr.com/photos/65036619@N04/6961520800/)
IMG_5080 (http://www.flickr.com/photos/65036619@N04/6961520800/#) by ricknieto (http://www.flickr.com/people/65036619@N04/), on Flickr

I've ordered new rotor and pads but I'd like to be sure this doesnt happen again. Any insight as to why this happened and how it could be prevented would be greatly appreciated.

Thanks!
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Speeddog on April 23, 2012, 03:37:29 PM
You've run the rear pads down to the metal, that's why the rotor is scraped up.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Slide Panda on April 23, 2012, 03:47:31 PM
Dude - have you ever checked your pads before? You have managed to wear them past the min, past zero friction material down to the point that the rotor has worn into the pad backing plate.

You need a new set of pads and a new rear rotor.

Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 23, 2012, 04:23:25 PM
Yeah I just realized this as I looked for the wear indication grooves in the pads that are obviously gone by now.  I had my 6000 mile maintenance done at the Duc shop last year and they said my pads were still good then but obviously I wore them down in the past 2000 miles. (I'm at 8K). How often should you check your pads? I've ordered new pads for the front too and plan on putting a new rear rotor and all new pads on.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: ducpainter on April 23, 2012, 04:32:19 PM
Quote from: Duck Off on April 23, 2012, 04:23:25 PM
Yeah I just realized this as I looked for the wear indication grooves in the pads that are obviously gone by now.  I had my 6000 mile maintenance done at the Duc shop last year and they said my pads were still good then but obviously I wore them down in the past 2000 miles. (I'm at 8K). How often should you check your pads? I've ordered new pads for the front too and plan on putting a new rear rotor and all new pads on.
I guess brake wear is dependent on riding style and brake usage, but I have 30 isk K on my bike and I think I'm on my first replacement set and they're fine.

Have you made any changes to the rearsets, or adjusted anything?
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 23, 2012, 04:53:46 PM
Its a new bike for me so I may have been riding the brakes a bit hard. Thats all I can think of.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Howie on April 24, 2012, 02:52:47 AM
The OEM rear pads on my bike lasted 12K,  The EBC HH on my bike have 30 someodd K and are only half worn.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 24, 2012, 06:13:46 AM
Yeah kind of weird. The change was removing the rear wheel for a tire change. I did ride before the tire change and there was a noticable difference in the rear tire braking after the tire change. I had to push all the way down to get any stopping power. I noticed right away as soon as I pulled out of the driveway. I figured it was probably just due to the brake fluid not being in its normal state yet and that it would normalize after a little braking but it didnt and the overall effect was I scraped up my rotors. My question is if my pads were worn out before the tire change why did my rear braking seem normal. How did a rear tire change make it so noticable or exacerbate this. Why didnt it scrape on the ride before the tire change. I'm hesitant to blame this all on the worn pads because otherwise I would've scraped the rotors before the tire change. What'dya think?
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Slide Panda on April 24, 2012, 06:47:42 AM
You're possibly trying to tie unrelated events together that just happen to fall at coincidental points in time.

You might have had a bit of pad material left around the time of the change - just a tiny bit that you've since killed off. You've worn them to the carrier plate, but just barely so it only happened recently or your rotor would be even more make the beast with two backsed.

I mean no offense - but you seem to be in over your head at this point. We lear though mistakes, but perhaps you want to get a more experienced buddy or a take the bike to a shop that's willing to spend a little more time walking you through the issues.

Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 24, 2012, 08:43:01 AM
Yep its a learning process alright. At this point I was just planning on putting on a new Rotor for the rear and new pads front and back. Seems fairly straight forward and theres a decent How-To with pics for EBC Rotor and Pads on this site. Any Gotcha's to this process I should watch for? Is this not as simple as it seems?
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Slide Panda on April 24, 2012, 08:53:10 AM
it is pretty simple - one thing that people skip on is cleaning. Be sure to give the pads and a new rotor a swipe with brake cleaner. Take a stiff plastic or (very) soft metal brush to the caliper - including the retaining pin and spring.

Don't rush and ensure everything is lined up correct when you reassemble.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 24, 2012, 08:55:12 AM
 [thumbsup] Thanks!
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: Ak1nza on April 24, 2012, 07:28:34 PM
Don't forget that you'll need to bed your new brake pads when you install them.  There are different ways to do this so do a search but here's one:

"Initially, the brakes should be used lightly (roughly 60-70% of normal) but frequently. As you feel the brakes come in, follow this with progressively harder braking to maximum pressure with momentary cool-down between applications.  The goal here is to impart an even transfer film layer from the new friction material to the operating surface of the rotor.  Do not try braking hard until they do and you are reasonably certain this is accomplished."



Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 25, 2012, 06:04:49 AM
Thanks for this information. I was not aware.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: seevtsaab on April 25, 2012, 06:53:07 AM
I would recommend completing the rear brake r&r and confirm you're happy with the performance before doing the fronts. Give the rears a good workout. Not that they'll ever give much stopping power but you want to be sure
everything is OK - be mindful that excessive sticking / rubbing can boil the fluid and lock the brake.
Title: Re: Help...Too much brake drag after reinstalling front tire
Post by: The ModFather on April 25, 2012, 10:20:00 AM
Also a great point I should've thought of this. As an engineer you never introduce multiple variables at the same time yet I was about to do both at the same time which I would never do at work. Thanks again!  [thumbsup]