| Author | Message | ||
     Buelljunkie |
Before I go any further, please know that I realize this is the tuber section of BadWeb, and it's where I spend most of my time, as I have several of them. My girlfriend, however, happens to have an 08 Firebolt. I posted our problem on the XBoard, but nobody's been on over there for almost a full day...so I thought I'd try over here, as the problem could apply to any bike. I did get some information from a search on "front brake lockup", but I think the few threads I found were at least 10 years old, so I thought I'd bring it up again to get some fresh discussion on the topic. Last fall my GF was walking her bike backwards out of the garage, and the bike slowly tipped away from her. She didn't drop it, but didn't have the strength to hold it up, so it slowly fell against the house and came to rest at about a 45 degree angle, snapping the stock front brake lever in the process. I had an extra set of stock levers from a 2009 Lightning and replaced the broken brake lever. It seemed to work properly, so I drove slowly down my street to test. Within a few hundred feet the front brake gradually but very quickly brought me to a stop, and would not release. I had to remove the brake lever to release the brake. I compared the original 2008 lever with the replacement 2009 lever, and I didn't really see any difference, although it looked like the tab on the lever which depresses the MC plunger could be slightly longer on the replacement than on the original. More recently, I bought another stock replacement lever for XB's on eBay, but am unsure of the model year of the replacement. I installed it, and it works fine pushing the bike around the garage, but I gave another test ride yesterday and the front brake locked up again, only it took about a mile to occur. I was accelerating from a stop, so I was not even on the brake lever. It felt like the bike was losing power, and when I released the throttle the bike stopped instantly. I removed the brake lever and the front brake released as it had done before. Am wondering now if there may be damage in the MC causing the issue, but the fact that removing the lever releases the caliper tells me otherwise. I inspected the rotors and they are somewhat glazed and there is a darker band in the center of the rotor surface, so it is apparent they were dragging. I'm guessing it was only slightly at first, but as the brakes heated up they just kept grabbing with more intensity. The bike has about 300 miles on it and is stored in a heated garage. The brake fluid is still very light in color, but has not been changed. My plans are to replace the brake fluid, and remove the rotor and hone it to remove the glazing. I can't see needing a MC rebuild, but am wondering if the caliper should get one. What do you guys think? Thanks a lot, Dave. | ||
| Maru |
It sounds like the lever you retrofitted is not allowing the fluid to return to the mc properly. I have seen this before. It is usually caused by the section that pushes against the piston in the mc being dimensioned differently. They may look the same and may bolt on, but my call is that the levers are not interchangeable. I would order the exact lever for that make and model. steve | ||
| Maru |
As a bit of elaboration, there is a bleed hole that gets covered by the mc piston if it does not fully return. As the brakes get used enough pressure builds up to activate the brakes. On some levers there is an adjustment that allows you to preload the lever a bit. If you go too far on this adjustment, it will do the same thing. | ||
| Ratbuell |
There is also a possibility that when the lever got broken/damaged, it could have transmitted some force/damage into the MC. Is the lever binding any? Is the brakelight switch operating properly? Are you getting the proper lever, as noted above? I forget when they changed to ZTL2...but if you have a six piston brake you need that lever because it has a different MC. If you have an 8 piston ZTL2, you need the ZTL2 lever to match its MC. | ||
| Buelljunkie |
Steve-I believe you are probably correct. The original lever and both of the replacements I installed were all stock levers. However, the replacement lever was from an '09 Scg which has a 4-pot caliper, and I put it on an '08 with a 3-pot caliper. Some guys are saying there is a slight difference btw the two levers depending on which caliper/MC you have. Dave | ||
| Littlebuggles |
"Some guys are saying there is a slight difference btw the two levers depending on which caliper/MC you have." Sounds like Rat and Maru have answered your question. As a follow-up, I 'd suggest once you make sure you've got the right lever, bleed the brakes, not only to cycle out the fluid (~five year old fluid) but more especially to make sure the master cyl is not binding or sticking in the bore. | ||
| Trojan |
You have definitely used the wrong lever when replacing the broken one. 2009 bikes fitted with 8 pston calipers use a lightly different master cylinder & lever (same as 1125 and tube frame bikes I think) than the early bikes with piston brakes. If you look at the fitting list from ASV you'll see that the 8 piston models use a BRC520 lever whereas the 6 piston models use a BRC530. If you use the incorrect lever it will stop the piston returning correctly in the master cylinder, build up brake peressure and lock the brakes. Buying used brake levers from ebay is not a good idea, as you don't know the model or if they hav suffered oprevious damage (and a LOT of ebay stuff is from damaged bikes!) | ||
| Ratbuell |
...and a brake lever is a cheap enough part to just buy new... | ||
| Buelljunkie |
Wise words and sound advice from everyone-thanks much to all for your time and your input. Typically I over-research just about everything, but I didn't expect there to be different levers on seemingly identical bikes. My bad. I'm lucky...my mistake could have turned out considerably worse. As it turned out there was no accident or injury or damage. Yes, very lucky I would say.(Yes, I was wearing full gear) And I won't be buying any more levers, even stock ones, off of eBay! I WILL be changing out the brake fluid, checking the MC, honing and checking the rotor, and replacing the pads...and ordering a new lever from Al. |
