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Front brake on Honda CBF 250 not very responsive

Discussion in 'Bling and Appearance' started by max.honda, Mar 2, 2009.

  1. Hi All,
    I've noticed recently that the front brake on my honda cbf 250 is becoming much less responsive. Obviously there is wear and tear and the disk pads become worn but I'm starting to get concerned. The bike has done 2000kms and was serviced at 1000kms. The thing that concerns me is how far the brake lever needs to be engaged before it starts to properly grip. At the point were it is fully engaged it touches outcoming tubes (metal) from the throttle. According to the manual of the bike the pads should be ok because they are still not worn to the mark (engraved line on the pad).

    Please let me know what you think! :)

    I wanted to attach pictures but I'm not allowed. :oops:
  2. sounds like air in the lines. how does it feel? Firm and smooth, or spongey? GEneral road riding, unless you ride the brakes, you should get at least a tyre's worth out of it. (Insert random variables here.)
  3. hi ray, thanks for the reply. i'm not quite sure what you mean by spongey but i guess it's not really firm and smooth anymore. actually, come to think of it more, i do have to press quite hard to get a solid response, and as i said, even then i'm not that confident in it's stopping potential. are there any other indicators of air in the lines that i could check for to confirm? the brake fluid level indicator is still in a high position (completely clear of the 'lower' mark). if it is air in the lines, is it possible to repair this myself?
    thanks again ray,

  4. if it is air which it sounds like it may be its a 10min job to bleed the front brakes. search front brake bleeding and you should find something. if i remember when i get home ill cut it out of a manual and paste it to you.
  5. #5 geeth, Mar 3, 2009
    Last edited by a moderator: Jul 13, 2015
    Heres a youtube vid on it.

    And heres something I stole from http://www.totalmotorcycle.com/maintenance/brakes.htm

    How to Bleed Motorcycle Brakes

    Tip: Any brake bleeding kit will do just fine but make sure you have a small bucket to put the tiny brake bleeder fluid container in as it is very likely to overflow.

    It is actually not very hard to bleed (renew) your own motorcycle brake fluid. This should be done at least every 2 years. Or when the brake fluid turns from clear to a brown to black colour (darker it is, the worse it is).

    Brake fluid will eat away at plastic and paint, be sure to cover any paint or plastic that may get splashed with brake fluid. Wipe any spilled fluid with the rag and lots of water.

    Step 1: Make sure you have the tools to bleed your brake fluid. The tools you require will vary, but generally this is what you will need:

    A. Wrench/Spanner (average 10mm)
    B. Brake bleeding kit (rubber fitting, clear hose, small container)
    C. Brake fluid overflow container (to put the brake bleeding kit small container in)
    D. Rags
    E. Brake Fluid (check what type of brake fluid you need for your bike. e.g. DOT 3). Make sure to buy enough brake fluid in the DOT type you require. (500ml should be more than enough).

    Step 2: Attach the brake bleeding kit to the brake fluid nipple located on the brake caliper.

    Step 3: Loosen the nipple so the fluid is free to flow down the brake bleeding kit tube and into the small container

    Step 4: Remove the master cylinder cap (top) so you can monitor and refill more brake fluid into the master cylinder as you bleed the brakes.

    Step 5. Pump the brake lever so the old/new brake fluid is forced through the tube into the brake bleeding kit fluid container

    Step 6: Keep the volume of the master cylinder constant (near full) as to not have it empty. Keep pumping on the brake lever until the fluid coming out is clear (rather than the old brown/black colour).

    Step 7: Once all the tiny air bubbles are gone hold pressure on the brake level and re-tighten the brake fluid nipple to close it off.

    Step 8: Replace the master cylinder top cover.

    Step 9: Remove the brake bleeding kit from the cliper and use the rag with water to clean up any spillage.
  6. hi guys,

    apologies for the late reply. it's been hectic at work!
    thanks for the responses and all the info.
    i'll go and get myself the gear that i need to bleed the brakes and report back when i get around to it.
    are there any other indicators of air in the lines that i could double-check for to confirm?
    i was wondering as well what are the causes of air in the lines? could it have come from a bad service (at 1000kms), as I never had a problem before that service...


  7. forgot,

    here are some pics of the brake lever and brake pads:








  8. i've been told it can also be done this way, to get the air out of the lines remove the top of your brake fluid reservoir, cable tie your lever as if you were braking hard and leave it over night, any air in the lines should come out on top

    if your brake fluid is a dark colour its probably best to change it anyways

    also get the brake fluid thats recommended for your bike, its most likely a dot 4 or 5 type.
  9. Its a little hard to tell from the photos, but is the problem that the brake lever hits the adjuster for the throttle cable? It looks like it would hit that before it gets to the twistgrip rubber. Maybe the throttle assembly has twisted around on the bar and got in the way of the brake lever?
    If so , you can loosen the clamping screws in the throttle assembly and rotate it a little to ensure there is clearance, then tighten the screws to prevent further movement.
    If that's not the problem, most likely is brakes need bleeding.
    Certainly your pads are not badly worn, and even if they are they should still work well.
    Good luck!
  10. Yes, the brake lever rubs up against the adjuster for the throttle cable (I assume this is the metal tube which houses the throttle cable coming out from the throttle assembly?).
    I checked and the throttle assembly does move slightly. I'll loosen the assembly and angle it upwards, so that the adjuster is further away from the brake lever.

    This sounds like a good solution, avoids having to purchase the bleeding kit and the hassle of actually bleeding the lines.
    I suppose though, as the bike has done around 2000kms it might be a good idea for me to actually bleed the lines properly with new fluid.

    I'll let you guys know how it goes. Thanks again for all the help. :)

  11. The cable tie overnight thing is usually a very temporary solution.

    Bleed the brakes, just do it. They sound like they need it done properly. If that doesn't sort it out, braided lines might be the go.
  12. Depends on where you live Max (in syd) I'm happy to give ya a hand bleeding brakes and checking them out one weekend (possible week night).
  13. Is the cbf brake adjustable? If so is it on the tightest position (1), if not play with that. The brakes/pads shouldn't have any issues with so few kms. Shouldn't even need a bleed yet. However, don't forget that if you have been very gentle on the brakes they will glaze over and I'm guessing thats happened here.

    If I were you I'd grab some brake cleaner and spray that on (avoid painted surfaces) discs, etc. then use this as a chance to practice emergency braking, doing so will help remove the glaze.

    Still issues after that I'd bleed the brakes. As a side not tyre pressures will effect braking so maintain those.
  14. It may have been interesting to see your rear brake pad as it could indicate what proportion of your braking is done front/rear. Like many people, including me, I do a lot of filtering. I find the rear brake better for picking my way between cars but I tend to drag the rear brake like an anchor as it seems more stable than using the front brake. I have replaced the rear pads thrice in 25,000 and the front twice. Check your rear pads. You may find they have double the wear og the front. It may be that you haven't used your front brakes really hard yet. Riding at low speed in heavy traffic usually means a lot of low speed. frequent low pressure front braking. This could create glazed pads. Were you able to get near to front lock-up before the lever became spongy? If the front pads are glazed then you may need to change your riding style to use your front brakes more vigorously on a regular basis. This will break through the glazing. If you can't do this with your currently level of confidence and skills, the brakes will continue to be glazed and when you come to avoid running up some one's arse you may be in trouble. If you are not using the front brakes properly then perhaps a riding course such as Stay Upright or an on track course will be good.
    All riders should know their bike's lockup point if they haven't got ABS.
    I know I have taken this post a bit off topic but hey, if the the pads are glazed there has got to be a reason. Of course, the pads may not be glazed so just change the fluid and bleed.