Front brake problems

[placidfemme]

Hi,

I have a 1992 Kawasaki ZXR 250, I havn't owned the bike for very long, only about 7 months. The ZXR has had a service and WOF (Warrant of Fitness) check less than 3 months ago, and now I'm having a problem with my front and back brakes... mostly the front brakes though.

I've noticed that when I ride (long or short distance) there is a light white coloured smoke coming from somewhere down near the front wheel. Being a relativley newbie rider I put it down to over reving the bike (because it has a quarter turn throttle), now that I am confident with my riding I know it is not because of over-revving the bike.

I called up the bike shop who serviced my bike, and told the mechanic I dealt with about my problem, he knows I'm fairly new to riding and put the problem down to over use of the front brake and advised me to equally distribute my braking between front and back brakes, which I thought I had been doing. I focused more on my braking, taking more care to ease into braking gently and to use both brake.

However, this is not helping and I'm still seeing smoke coming from the front end somewhere when I stop my bike.

Another thing I have thought of is that maybe the front brakes are not releasing after I have released the hand brake. This is the only other thing I can think of.

If anyone can give me any suggestions on how to narrow down this problem or fix it that would be greatly appreciated.

Now to the back brake. Considering that I got the bike serviced not so long ago, I'm assuming that all my parts should be in fairly good condition, after being told to equally distribute the braking (which I did and still do) I've noticed that when I brake, and exspecially when I brake suddendly (as you do when tin top drivers somehow don't even notice you on a bike) that my back brake thuds and feels like it is not connecting... could this mean I need new brake disc's?

Sorry if these questions seem very "newbie" but all help is appreciated.

Thanks in advance

placid

[2WheelFun]

Welcome!

Smoking brakes are not good! Having used the front brake like you do...is the front rotor dis-colored...looks kind of bluish in color? You can also tell if the brakes are dragging when you stop the bike...reach down and feel the front rotor with the back of your finger tips...be careful...if the brakes are dragging the rotor will be hot to the touch and could burn you. If your brakes are sticking...you should take it in and have the mechanic look at it.

Have you checked your brake fluid reservoir lately? If not...open the top and look inside and check both the color and the fluid level. Top it off if needed. If the color of the fluid is dark..you will want to change the fluid.

[placidfemme]

Thank you for replying... I feel a bit dumb but... The front rotor... Could you please tell me what that looks like, I'm not the brightest crayon in the box when it comes to all the different parts.

I will check the fluid before I leave work (at work right now). The little container that holds the brake fluid is clear and the liquid is above half, by memory it is darkish, but I will double check before I leave...

Another thing I forgot to mention was that when I got the bike serviced the mechanic noted that there was a little too much oil in the front forks, when I asked him about it, he said it was ok and I didn't need to worry about it... could that have something to do with it?

Thanks again

[Redline]

Might have blown a fork seal and it's dribbling down into the brake caliper. Happened on mine too, but I never saw any smoke....

[placidfemme]

A fork seal? Would I be able to see that on my own or would I need to take it into the shop?

Oh and the brake fluid is at 3/4 and is a light colour not a dark colour...

Good news is that it didn't smoke this morning when I got to work...

[Chromequeen]

Originally Posted by placidfemme

Thank you for replying... I feel a bit dumb but... The front rotor... Could you please tell me what that looks like, I'm not the brightest crayon in the box when it comes to all the different parts.

This too will pass Placid, and you'll be helping someone else someday who asks a similar question. Keep asking! It's the only way you learn.

[Tazzzie_]

Tee heee heee,

rotor is what the americans call a brake disk
took me a few posts to figure that out.

From what i read recently, there should be no such thing as over using a disk, front or back. not in general terms anyway. like you should be able to use the front or back disk which ever is your preference any time you like, but not constantly for long periods (as in for more than 15 seconds+) per braking.

maybe there is crud building up on the disks that is burning off ? but that said i did have an issue like that in my car where the emergency (hand) brake was sticking on, and it did cause smoke. How is the bike when turned off, and pushing ? can you feel any drag ? is it quiet or can you hear a friction noise

welcome btw - there are nice people here, hope you enjoy.

Tazzzie

[Tazzzie_]

o, just a side note, if everything is new, as in new pads, and disks (even used disks with new pads) these things take a while to "bed in" and maybe thats the problem ? I recently got new front disks and they are still bedding in.....

Tazzzie

[IFixAircraft]

You might try to lift the front of the bike when the brake is smoking to see if it turns freely. Just rock it over while it is on the side stand. You might need a helper. If the wheel does not turn freely then the disc is dragging. A common problem to make that happen is a small spec of dirt getting lodged in the return hole of the front brake master cylinder. There are two holes inside the master cylinder. a large one that supplies the master cylinder with fluid and a very small (smaller than a sewing needle) one that allows the pressure to release from the front brake caliper. If it is clogged the brake caliper will stay applied.

Good luck

Tom

[placidfemme]

Hi, thanks for all the help. I have called up the bike shop and should be taking my bike in on Friday to get it checked out, he quoted me $112 to take the calipers aparts and check them and if I need new brake disc's an extra $45 each

There is also a guy who runs our IT department here at work and he builds cars to race (I know cars are different to bikes), but he had a look, and by what he could tell the brakes are not releasing after use and he said that would explain the "dragging" feeling I get when I try to take off again after stopping... He also had a look at my front forks and said thier is no oil leakage and showed me how to tell if there were (Yay I learnt something new today... oh and that Americans call a brake disc a rotor haha)...

thanks again all and I'll let you know on Friday what the mechanic says about it...

[placidfemme]

Well I took my bike in this morning to the bike shop, and Mike (My mechanic) took her for a ride, and speed up towards me and braked as hard as he could, locked the front brake and skid my bike over a meter and rubbed off a layer of my nice front tyre... he did a bunch of other things to the bike, and politley informed me that he cannot replicate the problem and doesn't see any smoke nor where it might possibly be coming from. He said my brakes are fine and have a lot of braking left in them, he said they are not binding and the only thing he can think of is oil or petrol or something somehow splashing on my brake disc's while riding...

My bike still feel's like it's dragging and it was smoking just yesterday... so I'm stumped and not completely happy with the out come... at least I didn't have to fork out any money to get it fixed... but would have much rather payed him to do something then pay with my life later...

Confused rider

[T-man]

Ride it over and I'll have a look...

Seriously, you need badly to become better than novice in bike mechanics. Get a SERVICE manual and read it, starting with the section on brakes. You have access to the internet so you can get on the HowStuffWorks website and see how a car brake works. The principle is the same for motorcycles. You can start learning before the service manual arrives...buy one off the internet, it's cheaper. You do not want to take your bike to a shop for "service" every time it hiccups. They will bleed you dry!

AND, keep asking about stuff on this forum. We can advise from afar, but you must do some things yourself to learn and be a better motorcyclist for it.

[T-man]

Oh, by the way...regarding braking...hopefully you know how to "engine brake"...saves wear and tear on the brakes enormously.

[Green Knight]

Originally Posted by T-man

Oh, by the way...regarding braking...hopefully you know how to "engine brake"...saves wear and tear on the brakes enormously.

Eh... Its cheaper to replace breaks than it is engines. After I started racing I tookt he advice of better guys than me. I don't engine break anymore. I do my breaking and down shift twards the end of the breaking cycle. Engine breaking isn't quite as big of a deal for just puttering around town but in high spirited rides down shifting too soon can cause you to ping the RPMs over the rev limiter causing nasty engine damage. I'm not that great when it comes to rebuilding engines but I can put on new disks and break pads.

[placidfemme]

Engine braking? I've heard that so many times...

But...

I honestly don't know how to engine brake. I'm assuming it's something simple, if you could explain it to me I can try it out if you think it will help. As GK said... I don't want to ruin my engine, but if I don't over do it, it should be fine... right?

Also, where can I find a service manual? My bike didn't come with anything, no original papers, manuals or anything. I'll be more than happy to read up on anything I can...

[placidfemme]

P.S. While at the bike shop, I did ask the mechanic how I should look after my chain and sprocket, and he showed me how to prop my bike up... so I have learnt one new thing today... oh and I now know that a certain cable that runs to my front wheel is for the speedo... hehe

[Green Knight]

Engine breaking is just down shifting and letting the engine slow you down. No real harm at lower RPMs but its not something to rely on at high speeds or in emergencies. In an emergency stop (especially with sport bikes) your rear tire is not going to have much weight on it at all if any. Infact when I'm racing my rear tire comes off the ground a little. So applying any rear break or down shifting to slow you more will only cause a rear wheel slide or sometimes a hop. Its hard to control a bike when you're rear tire thinks its a basketball. The only instance where down shifting won't be so bad is with a slipper clutch. Those come stock in the new kawasaki ZX-6RR, 6R, and 10R. Basicly what they do is limit how much torque is going to your rear wheel when down shifting to help eliminate the slide and hop. Believe me, once you go slipper you'll never go back .

[placidfemme]

Oh.. thats what engine braking is... I do that when going down hill's but thats about it... I don't think my bike has a slipper clutch...

Unfortunaly for me I still have about another year before I can get a bike bigger than 250cc because of our restrictions here in NZ. But thats ok. It gives me time to save to buy a ZX6R. I want a blue one

[Green Knight]

No, you couldn't even put a slipper clutch in a 92 bike. They are a relatively new upgrade. Unless you race or ride twisties really hard you'd prolly never even notice its there unless you accidently down shift at too high of an RPM. The reason that they are so nice is that I don't have to worry about matching engine revs when down shifting coming up to a corner. If you've never experianced a wheel hop it would be hard to explain just how cool a slipper clutch is, hehe.

[placidfemme]

lol it's ok I can imagine... it doesn't sound very fun... I have had my back wheel bounce off the ground after hitting a pothole in the road while taking a corner, I saw it, but too late and couldn't right the bike before I hit it, and I felt my back wheel bounce and swing to the left then hit the ground again... it wasn't a very nice feeling... I was almost sure I was going to fall off... luckily I didn't