Author Topic: Front end rattle - brake caliper mount  (Read 557 times)

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Offline The Lone Builder

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Front end rattle - brake caliper mount
« on: May 12, 2019, 11:59:42 am »
My bike developed a rattle at the front end, starting intermittently, but quickly becoming continuous - in the sense that every time we hit a bump it rattled. I traced this to the brake caliper mounting bracket.

This was dismantled, the tattered o-rings - one was in fact torn – replaced and a copper washer put in at the top end  of the pin. 500 km later the situation was as bad as ever.

Another dismantle and this time a thin wire was wound around the pin to supplement the washer that looked a bit crushed. A thicker split pin was also inserted.

500km later, bad as ever!

Now I’m back home - oh, forgot to mention that this all happened on a 4,500km road trip that I’ve mentioned elsewhere. I searched the forum and discovered that this is not an uncommon problem.

I dismantled everything, yet again and did a few measurements. The holes in the mounting arm were clearly ovalled  and the pin itself worn - 9.7 vs a nominal 10mm. The o-rings, replaced only 1,000km ago were tattered.

I had a spare bracket and measured it up, not that this was necessary because there was no play to talk of, but the hole was round and the pin measured 10mm. There were also no shims in this one as compared to the “old” one which was shimmed to a total of 0.15mm.

Hopefully problem solved.. I just worry now if the replacement bracket will go the way of the original on Africa’s roads.




CB750 K2 - No longer running, now we’re flying!!
CB750 K1 - The less, said the better!
CB450 K1 - Stalled.
CB400F Supersport - It's rusty!

Follow my journey through Africa @ http://Belfast2BelfastByBike.com

Offline 754

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Re: Front end rattle - brake caliper mount
« Reply #1 on: May 12, 2019, 12:20:54 pm »
Once it starts to wear, it wil wear very quickly, it's likely bouncing back and forth in there.
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Offline Johnie

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Re: Front end rattle - brake caliper mount
« Reply #2 on: May 12, 2019, 01:35:28 pm »
I believe Honda issued a tech bulletin on that and putting a shim in there.
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Offline my name is nobody

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Re: Front end rattle - brake caliper mount
« Reply #3 on: May 12, 2019, 09:50:16 pm »
I believe Honda issued a tech bulletin on that and putting a shim in there.



They did, and I saw it on here someplace, but can't find it now. Raul Guellego (sp)?
posted it. Could a steel insert be machined by someone to combat this condition?
Maybe using the bushings from a car door? I have never tried, just throwin it out there..

Offline mattsz

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Re: Front end rattle - brake caliper mount
« Reply #4 on: May 13, 2019, 07:29:53 am »
I believe Honda issued a tech bulletin on that and putting a shim in there.

Found this posted on the UK SOHC forum - is this it?


Offline The Lone Builder

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Re: Front end rattle - brake caliper mount
« Reply #5 on: May 13, 2019, 11:37:27 am »
I believe Honda issued a tech bulletin on that and putting a shim in there.

Found this posted on the UK SOHC forum - is this it?



What did you find? There was nothing showing in my view.

Rapid wear is right. From no noise at all to something reminiscent of a train going over the tracks, but without the rhythm, in a couple of thousand km’s.

The old one I took off did have shims in place – 1.5mm in total. The holes were ovalled though: 10.48/10.3 and 10.01/10.2 and teh pin measured 9.72mm

The replacement bracket has no space for shims; the holes are round at 10.01mm and the pin 10mm.

 Fingers crossed.
« Last Edit: May 13, 2019, 12:15:02 pm by The Lone Builder »
CB750 K2 - No longer running, now we’re flying!!
CB750 K1 - The less, said the better!
CB450 K1 - Stalled.
CB400F Supersport - It's rusty!

Follow my journey through Africa @ http://Belfast2BelfastByBike.com

Offline mattsz

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Re: Front end rattle - brake caliper mount
« Reply #6 on: May 13, 2019, 12:28:17 pm »
What did you find? There was nothing showing in my view.

Huh.  I posted a link to a jpg scan of the bulletin. Not sure why you can't see it, the image shows on my screen, even in your reply's quote of my post!  I've included it as an attachment below, hopefully that will work for you...

Offline The Lone Builder

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Re: Front end rattle - brake caliper mount
« Reply #7 on: May 13, 2019, 02:11:22 pm »
Thanks.

All I see is a little square box.  ???
CB750 K2 - No longer running, now we’re flying!!
CB750 K1 - The less, said the better!
CB450 K1 - Stalled.
CB400F Supersport - It's rusty!

Follow my journey through Africa @ http://Belfast2BelfastByBike.com

Offline bryanj

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Re: Front end rattle - brake caliper mount
« Reply #8 on: May 13, 2019, 02:51:40 pm »
Has to be a problem on your system i got bulletin on dumbfone and laptop
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Offline mattsz

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Re: Front end rattle - brake caliper mount
« Reply #9 on: May 13, 2019, 03:01:01 pm »
Thanks.

All I see is a little square box.  ???

You can't view the attachment, either?  Huh.  Not sure how else to help, unless you want me to email it to you...

Offline mattsz

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Offline Don R

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Re: Front end rattle - brake caliper mount
« Reply #11 on: May 13, 2019, 03:23:07 pm »
 Thanks, I have that rattle on a sandcast.
No matter how many times you paint over a shadow, it's still there.

Offline morini

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Re: Front end rattle - brake caliper mount
« Reply #12 on: May 13, 2019, 04:20:57 pm »
Drill a hole, tap a thread, insert a grease nipple...


« Last Edit: May 13, 2019, 07:02:13 pm by morini »
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