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Author Topic: Why Can't i stop??  (Read 1978 times)

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Offline bmaker

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Why Can't i stop??
« on: June 13, 2012, 06:01:36 AM »
I am having trouble with my brakes.  I have rebuilt the calipers, installed new pads and bled properly.  Both the rear and front hold good pressure so I am pretty sure the MC's are good.  The issue is when either brake is applied, it has virtually no stopping power.  I have to litterally stand on the rear pedal to get the rear to lock.  The front isn't much better.  The only thing I have not replaced are the hoses.  Before I spend $100 on new lines, I would like to get some opinions on what could be causing this.
Thanks
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Offline LesterPiglet

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Re: Why Can't i stop??
« Reply #1 on: June 13, 2012, 06:05:39 AM »
How many miles since the brakes were replaced? They need a certain amount of bed-in time before they become fully effective.
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Offline hondaface75

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Re: Why Can't i stop??
« Reply #2 on: June 13, 2012, 06:07:18 AM »
You might as well give your year and model. If the hoses are original and on a vintage honda, chances are, they arent any good. The hoses flex, so youll loose some pressure there. But even if you have cleaned and rebuilt the caliper and MC the lines could be clogging up your fluid right after you did all the cleaning. Im sure someone else will chime in here.
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Offline bmaker

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Re: Why Can't i stop??
« Reply #3 on: June 13, 2012, 06:39:22 AM »
Sorry about that.  76' CB 750f.  Not sure if the hose were replaced by the PO.  Bike has about 22K miles on it.  I doubt the pads are bedded in yet but even now I expected some stopping power.  Hoses are the last thing in the system that isn't new. 
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Offline LesterPiglet

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Re: Why Can't i stop??
« Reply #4 on: June 13, 2012, 07:02:49 AM »
Are the pads/shoes contaminated? You need to start with the basics.
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'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


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Offline flybox1

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Re: Why Can't i stop??
« Reply #5 on: June 13, 2012, 07:19:43 AM »
Did the brakes work well before you upgraded?
if yes, your lines are still ok (maybe, they're 35 years old. shoulda replaced them  ::) ), you've still got air in the lines and caliper.
-or-  you've got brake fluid or some other contaminant on the pads/rotor.
my guess is for both....

if NO, or you dont know if they worked, get new lines, start fresh and dont overlook one part of one of the more important components of your Honda

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Offline Really?

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Re: Why Can't i stop??
« Reply #6 on: June 13, 2012, 07:50:12 AM »
Is this a new to you bike and you are comparing the braking ability to a modern bike with modern brakes?
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Offline Romhog

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Re: Why Can't i stop??
« Reply #7 on: June 13, 2012, 07:54:29 AM »
Quote from: Really? on June 13, 2012, 07:50:12 AM
Is this a new to you bike and you are comparing the braking ability to a modern bike with modern brakes?

Yea, that's the first thing I thought to ask. First bike I had was a 1987 Honda Hurricane and then a 74 CB750... I was never happy with the brakes being "good" after having something newer. My Current 550 is better but I think that's only because It's is much lighter.
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Offline Don R

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Re: Why Can't i stop??
« Reply #8 on: June 13, 2012, 08:01:57 AM »
I added a second disc to my F and was dissapointed at first. I did re-use the old pads. After some seat-in time, they stop great.
 I'm assuming the lever feels like it is compressing the fluid and not squishy. Are the discs shiney? Maybe they need turned or at least scuffed to get the glaze off of them.

I'm not sure about the comparison to newer bikes. Many Honda CB's can squeal the tires on a stop, I don't know how much more brake you can use.
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Offline ChuckG750f1

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Re: Why Can't i stop??
« Reply #9 on: June 13, 2012, 08:02:50 AM »
I have a '76 CB750 f also.  The brakes may not be the best but they certainly stop the bike.
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Offline bjatwood

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Re: Why Can't i stop??
« Reply #10 on: June 13, 2012, 08:39:46 AM »
My K3's brakes are not bad at all considering the drum and 1 disc setup. I put EBC shoes on the back over the winter and I barely touch the pedal to stop. And the front brake applies with just a squeeze of the lever. I bet you still have some air in the lines. Try and send brake fluid UP to the MC from the bleeder, you will see the air bubbles come out and into the MC reservoir. This works real well on bleeding the air out
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Offline bmaker

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Re: Why Can't i stop??
« Reply #11 on: June 13, 2012, 08:41:00 AM »
Pads are brand new and neither the pedal or lever are mushy.  I have not done anything with the rotors so getting them turned is not a bad idea.  The hoses are the only thing that I think that could be suspect. When I bought the bike, both calipers were leaking so I really couldn't get a feeling as to how they "should" have been before I tore into it.  I don't expect it to stop like my BMW but I do expect it to be close to my Harley!  I definitely don't think it's a "they are all like that" solution.  Something is definitely wrong.  I think I'll spring for the hoses and have the rotors turned.  if it doesn't work then I'll just buy new sneakers every other week.
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Offline MCRider

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Re: Why Can't i stop??
« Reply #12 on: June 13, 2012, 09:05:41 AM »
Quote from: bmaker on June 13, 2012, 08:41:00 AM
Pads are brand new and neither the pedal or lever are mushy.  I have not done anything with the rotors so getting them turned is not a bad idea.  The hoses are the only thing that I think that could be suspect. When I bought the bike, both calipers were leaking so I really couldn't get a feeling as to how they "should" have been before I tore into it.  I don't expect it to stop like my BMW but I do expect it to be close to my Harley!  I definitely don't think it's a "they are all like that" solution.  Something is definitely wrong.  I think I'll spring for the hoses and have the rotors turned.  if it doesn't work then I'll just buy new sneakers every other week.
Other than what's been said, I suspect the pads. What brand? One time braking power should be pretty strong. You should be uncomfortable about locking it up. Modern brakes feel stronger as there is more tire. And with duallies and multi pads, less fade, but that's a multi use feature. One time braking should still be (potentially) scary.

Reread your posts and if the calipers were leaking you could have a residual brake fluid  film on the rotors. (just one? Oh just realized, fr and rr.) If so they may need to be ground, there is a forum member doing this. And the new pads may be polluted past use.

New hoses would be nice and recoommended. But the old ones only expand so much then they should be good. They feel spongy getting there, and don't get there as soon, but still should scare you.

OCICBW  IMO
« Last Edit: June 13, 2012, 09:09:54 AM by MCRider »
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Offline hondaface75

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Re: Why Can't i stop??
« Reply #13 on: June 13, 2012, 01:54:03 PM »
This came to mind as well, are you sure the pads are squeezing the rotor? You should be able to shine a light at them while squeezing the brake lever. Could be stuck open? I think everything else has been covered by one or another here.
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