I've got a new-to-me 96 that I've only put a few hundred miles on. I had it out for my first long ride last weekend and noticed something wierd in the brakes. I thought I had felt something not right there before but couldn't pin point what it is.
Whats happening is I'll apply the brake lever a certain amount (doesn't happen under light braking), and the bike will begin to slow down. But during the slowdown I can feel the brakes start to grab harder, and the bike slowing down even more. This is bad, I even locked up the front wheel once when stopping hard.
Could it be water or air in the system? It's expanding when it gets hot and then brakes harder? I *think* I can even feel the level pushing back into my hand a little bit when this happens.
Appriciate any ideas. I know previous owner had changed the brake fluid regularly, and I can see it's still clear.
I would guess that your fluid is contaminated with moisture. As the pads heat the fluid, the water boils off and creates a little steam bubble which expands and increases line pressure. But then again, what the hell do I know?
Either way it wouldn't hurt to flush and bleed. There's a fair chance that it hasn't been done in a while (if ever).
check calipers for being stuck they will need extra pressure to apply then move with the extra pressure check with front wheel in air apply light pressure then check for brake application should get harder to turn as lever is pulled in
kerplode, Apr 5 2005, 02:51 AMI would guess that your fluid is contaminated with moisture.� As the pads heat the fluid, the water boils off and creates a little steam bubble which expands and increases line pressure.� But then again, what the hell do I know?
Either way it wouldn't hurt to flush and bleed.� There's a fair chance that it hasn't been done in a while (if ever).
Would it be that quick? I have a hard time seeing that the temperature spreads so quickly. Doing two braking tests right after eachother wold clarify this. If it does the same thing twice it's not the water (but bleed anyhow). Brake pads warming up shouldn't be this annoying and could be checked with double braking procedure also.
Is one side hotter than the other after a ride? Is one side HOT, even after limited braking? Is there uneven wear of pads? (This is a symptom, not a cause - check caliper!) Are the pads installed correctly? I think that, after a test and analysis ride, I would just take the calipers off and see that all the stuff is moving like they should. Flush and bleed is sound advice.
Water in the system turning to steam would NOT make the brakes work better!!! In fact the reverse would be the case!!!!
You get a harder feel after you get rid of the air / water!!!
As the cold brakes heat up (remember the original post was that it doesn't happen on light applications, only when breaking heavily), they get into their working range and as their efficiency increases you get better retardation.
I would suggest that zirconox has a �racier� set of pads in and if he isn�t the racer type of rider, needs to swap back to something that has a lower temperature working range.
He may also find that in wet weather he has an even more pronounced effect that would be very dangerous indeed.
As I said he should identify the pads and find out what he has.
Having said all that a bleed certainly won�t hurt but it won�t fix the problem, only a change of pad will.
What vfrgreg said, and also: as you slow down, there is less kinetic energy, so you need to apply less force to the lever to achieve the same brake force.
Unless you are in an emergency situation, you automatically apply less force to the lever when you slow down to maintain the same slowing down.
Yes I was daft with the wateriness also :blink: the rest applies however. Still don't think pad temperature has got anything to do with it. The less brake needed as the bike slows down theory makes sence only if it was the first vehicle ridden. If it feels strange there must be a reference. Brakes gripping so hard as you slow down that you lock the front wheel is bad. To apply more preassure as you brake is what you should do when braking hard. The brakes however shouldn't do it for you.
Swiffer, Apr 5 2005, 07:47 AMYes I was daft with the wateriness also :blink: the rest applies however. Still don't think pad temperature has got anything to do with it. The less brake needed as the bike slows down theory makes sence only if it was the first vehicle ridden. If it feels strange there must be a reference. Brakes gripping so hard as you slow down that you lock the front wheel is bad. To apply more preassure as you brake is what you should do when braking hard. The brakes however shouldn't do it for you.
Well I was braking pretty hard when the wheel locked up. Still it was a surprise. I've been riding for almost 10 years, owned 5 or 6 bikes, and have never locked up a front wheel before.
Could I tell if it's just racy brake pads? Are the pads labeled somewhere that I could tell what kind are on there?
Other than that the first thing I'll probably do is change the brake fluid and see if that helps.
zirconx, Apr 5 2005, 11:35 AM Could I tell if it's just racy brake pads? Are the pads labeled somewhere that I could tell what kind are on there? -Ryan
Cold... racing pads have an inital soft bite... but after a couple of heat cycles they bite progressively harder...
I would raised the front wheel off the ground and report back how well the brakes release... checking how easy the wheel spins after the brakes are applied is a necessary trouble shoot step when pin pointing any braking problem...
I vote that you have some kind of fancy brake pads, and you should replace them with stock pads. While you're at it, change the fluid, because that's always a good idea and you have a baseline for future maintenance.
I would leave the pads on and flush out the brake system with new fluid. Use the Honda approved fluid.
I used to see this on my '96 when it was time to change the fliud. I ran the Motul 600*. It with braided lines it was good for about 6 months. It is known for absorbing moisture into the lines. I also ran EBC Green Stuff pads. My '96 would regularly lock up the front and it was much to heavy to do a stoppie.
Ok so I went to flush out the brake fluid tonight. I hooked up some hoses from the caliper bleed bolts, opened up the master cylinder, and cracked open one of the caliper bleeds.
Lots and lots of air coming out. I can see it in the stream of fluid. In fact, the air never stops! I went through a whole bottle of brake fluid! What am I doing wrong?
On top of that, I tightned the bleeder back up, and tried the brake lever to see if it was any different. I have no brakes now! I can feel the lever is not pushing anything. I know it usually takes a few pumps to pump them back up after working on brakes, but I pumped the lever like 20 times and it's still moving freely.
does the fluid slowly bubble in the reservoir from the port??? i had to sit there for a loong time -at least 20 min- wiggling the lever and getting it to bubble out the top. then the lever started to get some pressure back. take your time because bleeding down will trap air in the system. better to bring all the air to the top.
I'm not trying to be a wiseguy but you are closing the bleeder between pumps, right?
Actually for the most part I was gravity bleeding it. Just crack the bleeder and it runs out. But after running half a bottle of fluid through it I started pumping, and yes I was closing between pumps. I watched the hose full of fluid and bubbles and none got sucked back in.
dirtbag, Apr 13 2005, 09:21 PMdoes the fluid slowly bubble in the reservoir from the port??? i had to sit there for a loong time -at least 20 min- wiggling the lever and getting it to bubble out the top. then the lever started to get some pressure back. take your time because bleeding down will trap air in the system. better to bring all the air to the top.
No, no bubbles from inside the master cylinder. I talked with my father about it tonight, he was a mechanic for many years. He said it sounded like the master cylinder might be bad.
Anyone know if Honda makes a seal replacement kit for the front master cylinder, or if I have to buy a whole new master cylinder?
[whine]I've had this bike 5 weeks and only put 400 miles on it, it's been nothing but trouble since I got it. I wish I would have waited a few years and saved up for a new one.[/whine]