| Author | Message | ||
     Suaverider |
Hello, My front caliper is rubbing on the outside of the rotor (right side of caliper). I have new brake pads installed and when the wheel and caliper are tightened, it rubs bad. Can hardly turn the front wheel. How do you center the caliper? I can't seem to get it in the right position. This is on a 2000 M2. Thanks | ||
| Jackbequick |
Do you have a service manual or parts book that shows that all washers or spacers are in the right place? If so, it may be that the pistons are not retracted enough. Sometimes that can be caused by a crust of brake pad residue encircling the piston. The pistons were further extended because of the wear on the old pads and the new pads require the pistons to be retracted further. You may be able to clean the ring off with a soft bristled brush like a toothbrush (a M-16 rifle Nylon cleaning brush is perfect for the job if you have one, no shop should be without a few of those). You have to be careful when you put any pressure on the brake lever with the rotor our of the caliper. You can extend pistons beyond normal travel, expose the seals, vent the fluid/pressure, or push the piston right out of the caliper. There is nothing to keep the pistons from traveling too far with the rotor out. And if you have the caliper off the bike and the rotor/caliper are not ridgidly held on their centerlines, the pads won't necessarily extend easily and equally from both sides when pressure is applied. You might try this, slip the old pads back in and clamp the caliper on the rotor (or on something just slightly thinner than the rotor). This can get all the pistons extended the same amount they were extended originally or a little bit more. Then use various soft brushes to brush all the pad residue out, use the Nylon brush to brush away all the residue around the sides of the pistons. At the end I'd use some aerosol brake cleaner on any stubborn spots. The $2 a can on sale aerosol brake cleaner is good stuff and won't damage the brakes (but watch out around painted stuff, wear nitrile goves, and have good ventilation for breathing). After the pistons are cleaned around the sides they should be able to fully retract more easily. Open the bleeder and push all the pistons back in until fully seated. Open the bleeder only 1/4 turn, putting a piece of vinyl tubing on the fitting will help capture the fluid to contain the mess some. Tilting the rotor or something of equal thickness in between the pistons will usually work to push the pistons back. If you don't push on or restrain all four pistons when you're doing this, the pressure on some of the pistons can unseat one of the others. It becomes a little like the Bash A Mole game. When that caliper is working normally, the pistons retract very little when the brake lever is released. The amount seemed to relate to the pressure used at the last application. My M2 front brake always dragged a little, I could hear it sometimes at slow speeds. But if I stopped, braked hard for a few seconds, then started rolling again, the drag would be less or gone. The amount of drag I was having was aminor annoyance. It was not enough to keep the rotor hot or cause it to discolor. When I had the front end up to work on it, the front wheel turned easily and the drag could still be heard a little. Here is a *great* thread in the KV http://www.badweatherbikers.com/buell/messages/3842/174272.html?1139415194 about front brakes. Henrik's method for sealing the bleeder screws with Teflon tape is one of the greatest ideas I've ever seen. It prevents air from being sucked in around the bleeder screw when you are bleeding the system and prevents a lot of the mess too. All my bleeder screws get Teflon wrapped now. I like the thicker yellow gas service tape (easier to handle/work with) but the white works good too. I use a Mity-Vac instead of Henrik's syringe in a otherwise a similar method for bleeding the brake. Hippy Joe's description of brake bleeding is good too. I miss my M2, especially the front brake. That was the best brake I've ever owned. If I ever get young enough again or want to have more than one bike, it'll be another M2. Jack (Message edited by jackbequick on September 29, 2006) | ||
| Djkaplan |
In my 1999/2000 Buell shop manual, the spacers for the front wheel are not shown in the correct positions. If you have this same shop manual, you have to switch the spacers around to get the wheel installed correctly. | ||
| Suaverider |
Thanks Jackbequick and Djkaplan. The caliper was rebuilt so there is no crudd build up it's very clean like brand new. The caliper just hangs too far to the right on the rotor. I just don't see any way to get it centered. When the mounting bolts are tightened, it just sits where it wants to. As for the shop manual, I did notice that the picture looked off. I have the smaller spacer on the right and wheel looks pretty well centered. I don't think the manual shows any washers just the two mounting bolts. Are there any kind of shims available to mess with the alignment? Still stumped. What a drag. | ||
| Reepicheep |
It's the spacers. I think they are wrong in both the service manual, and I think they might even be wrong in the parts manual. Or maybe the parts manual had it right... I can't remember (and sent both to the guy that bought my Cyclone). I remembering puzzling for a while, but finally working it out. I have a milk crate you can borrow to sit on if you want. I have found a cigar helps as well. One more note (that you probably know)... when you get it all together, you will have to pump the brakes up a few times before the front rotor actually will stop the bike. For most people this is not an issue, but I did my repair in a garage that lead right to a steep driveway. The "4 pumps" between when I started down the driveway and when the brakes started doing something were pretty exciting  (Message edited by reepicheep on September 29, 2006) | ||
| Bomber |
following the best tech writer practice, the illustrations in the service and parts manual are identical ;-{ sadly, they are identically wrong ;-{ these issues are known in the trade as "jokes" (please, no one tell, as they'll cut a corner off my tech writer card if they find out) with the wheel spacers properly installed, all *should* be well -- I don't seem to remember any washers/spacers involved in the caliper mounting . . . . I'd go back and remove the caliper mounting hardware, and reinstall everyone -- it's cheap, it's easy, and it may even help | ||
| Suaverider |
Would a wrapped rotor cause something like this? I can't tell if it's wrapped I'm just guessing. How would you know if it was wrapped? The spacers are very different from each other and am pretty sure they are in there right. I have the smaller one on the right side. Thanks | ||
| Bomber |
Suave -- easy to check for a warpped rotor get a coat hanger or similar hunk o metal, hold it next to the disk, not quite touching, rotate the wheel, and check for the space between the hanger and disk varying . . . . if the disk is up against the caliper all the way round, I can't imagine that being a warped disk I'm thinkin you got the spacers right -- one of the reasons the illustration was likely NOT fixed was because it's not possible to assemble the wheel as shown, so the on the ball wrench will reverse em | ||
| Reepicheep |
There's an easier way then that Bomber, I'm suprised at you, I even hinted at it in a previous post... Reassemble system. Pump up brakes to insure safe stopping. Start bike rolling down a steep driveway and reach for front brake. At this point, if the bike stops, you do not have badly warped rotors. If you find yourself frantically pumping up the brakes *again* for the *second* time in a day, trying to get the bike to stop in the next 20 feet, you have a warped rotor. Simple as can be! I know, I tried it! The spacers go over the axle on the wheel. I don't have the 2000 bike or manual anymore, so all I can say for sure is that the manual illustrations are the one way I know for *sure* it is *not* done. I am reasonably mechanically inclined, and a pretty good spatial thinker, and getting that caliper off the rotor and getting the spacers back in the right places to get things reassembled took a LOT more thinking then I expected given the limited number of variables involved... I was serious about the Cigar. | ||
| Djkaplan |
I had a front rotor pretty badly warped, and it didn't have the symptoms you described - I never had to pump the brake to get it to work. Maybe it wasn't warped badly enough to replicate the symtoms, but it was warped enough to make grabbing the brake scary at speed. | ||
| Blake |
There are some thin washer type spacers that need to fit between the caliper and its mounting bosses where the bolts screw into. Without those spacers correctly installed, the symptoms you describe will occur. | ||
| Reepicheep |
My warpage was not just "warped", it was "bent" by a tire installer at a Harley Dealer (who is now, no suprise, no longer a Buell dealer). It was not Eastside Buell, and was not F&S Buell. Made for a pretty exciting ride down the driveway... | ||
| Bomber |
Reep -- thanks for the Laughing Out Loud on a Monday! you're right, of course, but tech writers specialize in making things harder than they need to be ;-} this is why I grabbed a tire cherger mchine like thingie earlier this year -- pretty soon, I'll be making my own castings for parts -- then, all I'll need is a bauxite mine! I've got no washers under my caliper IIRC, never had -- hmmmm sadly, all this is likely NOT helping Suave much . . . . . | ||
| Blake |
Hmmm. Maybe the spacers are specific to the older models? Or if they stick to the caliper or mounting bracket, you might not ever notice them? Maybe not all front brake assemblies needed them, an as-assembled tolerance issue? | ||
| Djkaplan |
I can't remember any washers between the caliper and mounting boss on my 2000 M2. I'll check tonight... but I'm pretty sure there weren't any. | ||
| Henrik |
If I'm imagining this correctly and the rotor is rubbing on the outside pad, and the M2 caliper bolts to the inside of the mounting bosses, then shimming will not work as you can only shim the caliper *in*. I ran into this in my S2 dual disk travels. The right side rotor would rub the outside face of the cut-outs in the caliper due to too much off-set in the rotor. Anyway, I ended up taking 1 mm off the spacer pressed into the speedo pick-up. I guess all this leads up to a couple of questions; did you change your rotor? What brake pads do you have in there? The Lyndall pads seem to be a tad thicker than others, which could cause the problem you're having. Henrik | ||
| Blake |
You're right Henrik, the spacers would make his problem worse. My bad. | ||
| Bomber |
I went out to the Entropy Lab last night, checked the parts book, no spacers between the caliper and it's mounts. checked the bike, ditto I, too, had trouble getting Lyndall pads installed, but they did fit (beverage break, alnglo saxonism exercises and milk crate sitting all required) | ||
| Henrik |
I *did* use one shim on one of the mounting bolts on the S2, but we're talking 1/32" shim, and only to get the caliper properly aligned with the rotor. I'm still wondering why new pads would cause that problem - except for thicker pads bringing to light a previously existing off-set. Henrik | ||
| Djkaplan |
http://www.badweatherbikers.com/buell/messages/47623/230991.html?1159896021 |
