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VERY noisy calipers

1.9K views 23 replies 6 participants last post by  Thermodyne  
#1 ·
Hi guys,
I'm trying to sell my Evo softail custom bike but there's no way it will sell due to a mega noisy tinkling rattle coming from the single pot V.T. front calipers. It's so loud it's bloody annoying to ride.
The bike has aftermarket wide glide forks from the 90's, has a thick steel small custom front fender and a pair of single pot calipers. When ridden, the bike rattles badly from up front. The fender is very solidly mounted so the whole assembly is rock solid. When you remove the fender all goes quiet, the rattle is gone. I've tried to mount the fender on rubbers, to rule out harmonic vibrations causing the noise. Makes no difference. So I tested a theory that the fender was inducing the rattle elsewhere. I removed the front calipers (hung them from the bars) and test rode the bike. The rattling disappeared, even with front fender in place, which proved the fender wasn't where the rattle was coming from. So I must conclude that it is the calipers that are rattling, maybe caused by the fender. So, how can I stop the calipers rattling so badly? Is this common for these calipers? Can't sell it without a fender. This is the UK, we need a fender as its always raining here 🤣
The calipers don't appear to have any anti-rattle shims/springs etc like other calipers do. So I can't see what stops the outside pad rattling away inside the retainer plate. Any thoughts on how to quieten them down would be much appreciated.
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#4 ·
The lower leg mount is a big block of aluminium held by two large 1/2" c/sunk screws driven home tight, so rock solid. The noise sounds like a very tingling type rattle, similar to the noise made if you rattle the loose pad around inside its thick steel housing plate.
The loose pad is quite free to rattle in its plate. I can't see that small spring stopping the side to side movement. Should it maybe be bent more than it is?
 
#6 ·
Should the leading edges of the pad wear more? My pads taper slightly in thickness, from leading to trailing edges. Could this be causing the noisy rattles? Can't figure why removing the fender stops the rattling but with fender fitted removing the calipers stops the rattling.
 
#8 · (Edited)
I'm unsure which way the anti-rattle springs should face when installed in the calipers. Should the spring be acting on the friction material side of the pad, or on the piston side, as in, pushing the pad onto the rotor or pushing it onto the piston? They are currently positioned this way round. On parts diagrams for the calipers it suggests they might need to be installed the opposite side of the plate.
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#9 ·
Factory service and parts manuals. Essential to doing your own work.
Yeah, guys like me can do the job, correctly in minutes,, looks easy, because it is..writing it all out, when the info is available???
This was intended to make you think,, how you have those assembled is not close to correct,,, good luck
Brakes are not a system to learn on,,, loud rattles from the calipers could be the cause of a serious problem.
All could be solved with the manuals mentioned above.
 
#10 · (Edited)
Manuals are great things to have, when you know what bike you have. But here's the thing, this bike is a full custom build with aftermarket front end, aftermarket wide rear end, 3" BDL belt drive, Mikuni carb, etc etc. Pretty much all non-std parts. In fact the only thing that 'may' be from the original donor bike is the frame/engine/gearbox, and the frame number is on a plate and doesn't conform to ANY Harley frame numbers on the known tables. So, manuals? I don't think so. But then you wouldn't know this, but still chose to be smug after initially seeming like you wanted to help.

I asked a simple question about which way round a spring should be fitted as, from a quick look, it seems feasible to fit it either way round which, frankly seems piss poor design, based on Murphy's law.

As it happens, I bought the bike pretty much 'as is' and this is the first time I've taken these calipers off to investigate the noise. I've no idea who fitted them or whether they rebuilt them correctly, hence my question. And no, not having owned a Harley before, being UK based, and with a long lifetime owning, maintaining and customising many many Brit, Jap and European bikes (& currently building a new ground up custom XS650 based chop), I'm hardly going to be a connoisseur of Harley models and which calipers fit which models, am I. Hence why I was hoping to reach a knowledgable, helpful forum ear who might be kind enough to assist. Seems I was mistaken, unless of course you'd like to change your mind and help out. If you don't feel like helping a fellow biker out then why waste my time posting on my thread?
 
#17 ·
Sorry Thermodyne, what originally sounded like a rattle coming from the Mikuni carb area (local Harley mechanic tested bike and thought it might be from carb) generated my noisy carb thread. When I finally deduced it was caliper based I just thought a new thread with a more relevant thread title, in the right forum area, might direct my query better. I thought I'd closed my carb noise thread down with my last comment. Will bear it in mind next time 👍
 
#13 ·
Based on that one pad carrier, you have a problem with the slide pins.

Here's an exploded view of the parts.

View attachment 281267
Based on that one pad carrier, you have a problem with the slide pins.

Here's an exploded view of the parts.

View attachment 281267
Thanks for your thoughts. Not quite sure what you mean, as my slide pins look to be set up pretty much as that diagram. My lower pins move smoothly in the caliper casing, the O rings are in place and lubed up. The upper slider has its seals, lubed, and slides smoothly in the upper casing hole, so what is not right please?
This diagram (thanks for including it) shows the spring orientation better than other diagrams I've seen, and it's clear from the diagram that my springs have been fitted the wrong way round. Is this likely to be the cause of the rattle?
As I mentioned above, this is a totally non-std bike, and my first 'Harley', so my first experience of these Harley calipers.
 
#18 ·
Refitted the calipers, minus the outer pad itself. The calipers are solidly mounted on the sliding pin arrangements, no movement other than longitudinal and that is a good firm but smooth movement. So it has to be the outer pad rattling in its keeper plate. The backing plate for the outer pad is, by nature, a loose fit in its keeper plate. Maybe I just need new anti-rattle springs??
 
#20 ·
OK, so, I've refit the calipers, after rechecking them thoroughly, test rode the bike today and they still rattle. However, when i trail the brakes the rattle stops, which makes me think this is all to do with the anti-rattle springs not preventing the outer pads rattling in their keeper plates.
Do you have any suggestions for a cure please? Can't sell the bike if they're rattling.