Front Brake Disk Problem

May 25, 2006
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HuaHin
Hi Friends,

I wonder if you never heard about bented front brake disks, but it seems I have the issue on my HD Electra Glide Ultra Limited 2010...

Disks are slightly twisted and provoke jerkies when braking...

I would like to know if you ever encounter this issue, what could be the cause of it and how to fix it apart from changing the disks for new ones ???

Thanks in advance for your feedback.

Keep the power on.
 

DavidFL

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Chiang Khong
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Warped discs need to be replaced.
I had that on my Africa Twin once.
It maybe possible to skim the discs a tiny bit to reduce the warped effect, but they may make the discs too thin & below spec.

My non engineering 25 satang's worth.
 
May 25, 2006
771
22
18
70
HuaHin
Hi Friends,
Hi David,

Thanks for your answer, as always you're on top.

I do understand the issue of skiing disks and then have disks under specs, thus I decided to change it, a friend of mine will bring them back from Bangkok, to morrow but I really would like why this has happened ???

My mechanic -K Tchow, specialized in HD- thinks it could be because I wash the bike when disks were hot, with cold water...personnally I have difficulties to believe it but....who knows ???

Any idea ???

Keep the power on.

Laurent
 

canthai

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Apr 8, 2015
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Check that the caliper is fully releasing. If one side drags - or both - the heat can build up quickly. 6 or 7 years old now - have you ever had them serviced ? I.E. flush old brake fluid and replace.
 
May 25, 2006
771
22
18
70
HuaHin
Hi Friends,
Hi Canthai,

Thanks for the answer, I will check for the caliper, but yes it has been serviced and the change of brake fluid has been one of the first I did.

I was thinking to have air in the fluid, but in fact not and the change of brake fluid didn't improve anything...

Keep the power on.
 

scotty007

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Feb 23, 2004
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Usually they have got too hot, perhaps after descending a very steep hill where the gears of the bike were not sufficient to keep your speed down, or as suggested above the caliper has not released properly, best to service the caliper and change out the brake fluid, use DOT4 or DOT 5/5.1 brake fluid. You would also be best advised to put new brake pads in at this point since you are changing the disc.
 

canthai

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Apr 8, 2015
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And Murphys Law also comes into effect ! As the bike is 6 or 7 years old, this may have been happening slowly up to now. Warp a bit, then some more, then some more ... Good luck with the repair
 
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Aug 20, 2013
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Are your discs, floating discs? If so, the rings that go around the disc could be ceased. You should be able to rotate them. If not, try freeing them up with a suitable brake cleaner and a nut and bolt through the holes to rotate them.
IMG_6451.JPG
 
Last edited:
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May 25, 2006
771
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18
70
HuaHin
Hi Friends,
Hi Scotty007 & FaraGit,

Thanks for your reply and comments, in fact I achieved the change of my front brake disks, it cost me 8500 THB and one hour of work at my mechanic workshop who has all equipment and tools to do it.

It changes my life...everything is good again and I can conclude that it was the disks !

I still not understand how I could have dammaged them
IMG_20170128_094321.jpg

Now I recover the pleasure of driving safely and smoothly without any jerk.

Keep the Power On
IMG_20170128_094321.jpg
IMG_20170128_094332.jpg
IMG_20170128_094321.jpg
IMG_20170128_094332.jpg
 

canthai

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As the post above mentions - if you are in the market for new discs in the future - give serious thought to going to full floaters. Much nicer setup. My Dyna has dual PM discs and the stopping power is great. Was too great until I got used to them.
 

scotty007

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Feb 23, 2004
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Hi Friends,
Hi Scotty007 & FaraGit,

Thanks for your reply and comments, in fact I achieved the change of my front brake disks, it cost me 8500 THB and one hour of work at my mechanic workshop who has all equipment and tools to do it.

It changes my life...everything is good again and I can conclude that it was the disks !

I still not understand how I could have dammaged themView attachment 3862
Now I recover the pleasure of driving safely and smoothly without any jerk.

Keep the Power OnView attachment 3862 View attachment 3863 View attachment 3862 View attachment 3863
No worries, it is sometimes possible to realign the disc using a rubber hammer in the right spot, but results are never 100% correct! Enjoy!
 
May 25, 2006
771
22
18
70
HuaHin
No worries, it is sometimes possible to realign the disc using a rubber hammer in the right spot, but results are never 100% correct! Enjoy!
Hi Friends,

It's exactly what my mechanic did at the first attempt. He tried to correct them but when we refit the wheel, the test drive was not concluant. Thus I decided to change the discs for new ones.

Now it it's "Night and Day", it works perfect and I can stop the bike with no issue an ABS is working perfect as well. In some 50 years of riding, it' s the first time that happens to my bikes. Very strange and difficult to understand. Even on my Kawasaki 500 H, on which I had only one disk at the beginning (for a nice power) I did not had this issue....

Keep the power on