Brake Squeak

[liamstears]

First Happy New Year all

Got a squeak on the rear brake I've not had before and hope someone can help

Firstly I had a pulsing rear brake, wasn't right and I believed it to be a warped disc

Replaced the disc (used part), replaced the pads (New EBC HH), cleaned up the piston, reassembled with copper grease and replaced the brake fluid

Worked fine for a couple days till I noticed some loud squeaking coming and going from the rear

Chucked her up on the centre stand and let the wheel spin and what I found was a tight spot when turning on the brake and when the wheel turns and hits this spot it causes the caliper to raise ever so slightly but this in turn causes a squeak

What could cause this? Another warped disc a possibility?

Look forward to your suggestions

 

[TownsendsFJR1300]

Double check your assembly.

The rear brake bracket (see pic below), has a horizontal slot (maybe 1' wide). That slot
MUST fit into the squarish pin in the swing arm. It keeps the bracket / rear brake from rotating.

It's not difficult to miss it when re-assembling. If it ISN'T in the slot, re-assemble correctly and test.

Hopefully, it didn't get bent with 87' lbs of torque with the axle tightened down..




.



.Plz post back what you find...

 

[liamstears]

Double check your assembly.

The rear brake bracket (see pic below), has a horizontal slot (maybe 1' wide). That slot
MUST fit into the squarish pin in the swing arm. It keeps the bracket / rear brake from rotating.

It's not difficult to miss it when re-assembling. If it ISN'T in the slot, re-assemble correctly and test.

Hopefully, it didn't get bent with 87' lbs of torque with the axle tightened down..




.



.Plz post back what you find...

Thanks for the reply

Unfortunately not the problem though, have done this sorta thing a hundred times so aware of the pin and that's seated properly...

 

[TownsendsFJR1300]

Yamaha Motorcycle Parts 2007 FZ6 - FZS6W REAR BRAKE CALIPER Diagram

Is part #8 installed correctly and also (un-numbered), the anti squeal part at the front of the brake bracket?

 

[liamstears]

Yamaha Motorcycle Parts 2007 FZ6 - FZS6W REAR BRAKE CALIPER Diagram

Is part #8 installed correctly and also (un-numbered), the anti squeal part at the front of the brake bracket?

Yup, both installed correctly

Have triple checked everything

Have made a video to show you: https://youtu.be/p5valFsIEp4

I'm thinking maybe the used disc I bought it warped?

Thinking of buying a new disc...

 

[FinalImpact]

Are you sure all of the axle spacers are in place? #6, #7, and Qty 2, #19?

Can you see a gap between the rotor and the caliper holder on both sides? Something to the effect a 2 to 3 mm on both sides....
If so, I would advise turning the wheel by hand while holding something to the caliper holder and verify the rotor is true.

Here is the same concept but using a dial indicator. From Post #7 here: BRAKE BLEEDING, CALIPER AND PAD INSPECTION

***********************************
Checking Rotor Defection:
***********************************
I'm not going to go into detail on this but if the wheel leaves my sight I inspect it. Its MY LIFE AT STAKE and I trust very few with my life!

Hint: Wheel was off and out of my sight for tire replacement so I thought it worthwhile to check rotor trueness upon installation just to confirm nothing happened that I was not aware of.

Brake disc deflection limit:
0.10 mm (0.0039 in)

Measured
Inner - Outer radius:
RS = 0.0002 - 0.0004" Less than 1/2 distance between marks.
LS = 0.0008 - 0.0013"

Each mark is 0.001" so its within spec! Steel Quick Clamp in combination with the axle bolt made the Magnetic Base on the dial stay put! :thumbup:

Needless to say the sun was evil and with a white dial, didn't stand a chance of getting a clear photo of the setup and read the dial.
LS outer....

In short, you need the proper tools for the job. In this case, I improvised creating a base and getting the needle square to the rotor so the inner and outer edge could be checked for trueness.

***********************************

 

[liamstears]

Thanks for all the help

99.9% sure all those spacers went back in, if I wiggle the brake caliper so the pads loosen everything spins freely with no issues, its only when you use the brake and the pads get closer to the disc a problem occurs

Now I have a digital caliper and have just done some poking around to see what I can find and by no means were my measurements perfect but they do cause some concern and make me lean more towards a dodgy disc

Rear disc is suppose to be 5mm with a wear limit of 4.5mm, I measure around 4.6mm so very close to the limit
Runout is max of 0.15mm I believe, I measure a runout of anywhere between 0.1mm and 0.2mm

Maybe I just need to buy a new disc...

 

[FinalImpact]

If you take the pads out and place the caliper back in place, will the caliper slide back and forth the width of the pads? It is a floating caliper and needs to freely move from side to side on the pins.
Sometimes too much grease can be packed into the slide pin and basically hydrostaticly lock the caliper from sliding. You basically, pull it apart, remove some grease from the pins slide and that is the fix.

As for disc runout, when swapping discs there can be no burrs, debris, or raised edges between the mounting surface and the disc.

As for disc thickness, rarely is the rear brake used enough on a street ride to over heat it and warp it. Im saying this as it is unclear that it is the root of your problem.

 

[liamstears]

If you take the pads out and place the caliper back in place, will the caliper slide back and forth the width of the pads? It is a floating caliper and needs to freely move from side to side on the pins.
Sometimes too much grease can be packed into the slide pin and basically hydrostaticly lock the caliper from sliding. You basically, pull it apart, remove some grease from the pins slide and that is the fix.

As for disc runout, when swapping discs there can be no burrs, debris, or raised edges between the mounting surface and the disc.

As for disc thickness, rarely is the rear brake used enough on a street ride to over heat it and warp it. Im saying this as it is unclear that it is the root of your problem.

Yup moves freely, floating nicely

Cleaned up the wheel before mounting the disc

It is a used disc on the bike from a breakers and I have no history on it...

 

[TownsendsFJR1300]

Great video!!!!

It sounds like metal to metal. Very light, but just enough...

Pull the brake pads, reassemble and try your test again.

Look real close at the disc, caliber bracket, etc when apart. Somethings going to be VERY SHINY from rubbing..

I'll bet it still squeaks some where near the brake caliper.

You should be able to duplicate that squeak (with no engine), just rotating it back and forth at the "bad spot".
Shouldn't be too hard to find...(with or W/O the pads)

 

[TownsendsFJR1300]

Any updates???

 

[liamstears]

Have swapped the disc for a brand new aftermarket disc and that seems to have got rid of the tight spot, need to ride it and wear it in a bit and see how it goes but think it's fixed

Got a blown fork seal at the moment though so not riding it, fixing it tomorrow so will give another update after doing a few miles

 

[upshiftoverdrive]

I am having a loud rubbing noise coming from my rear brake only when the bike is pushed backwards. I have pulled the caliper a few times, new fluid, cleaned/lubed piston, the pads are only a few months old. I also adjusted the brake switch for travel.

Please watch this vid: https://www.youtube.com/watch?v=J2Q3F6q52xQ&feature=youtu.be

Pics: Imgur: The most awesome images on the Internet

I measured the disc in different places and it's always pretty close everywhere to 5mm.

I was thinking about pulling the caliper again and taking the pads and resurfacing them on some pavement like I saw Townsend suggest on another post.

Any thoughts?

-Thanks

 

[TownsendsFJR1300]

The pic, kinda hard to see, looks like the actual mounting plate(the large aluminum with the slot), looks awful close to the front by the disc.

At any time, was the wheel, axle assembly, etc, TIGHTENED DOWN with the slot NOT in the tab (potentially bending it)?

Do you HAVE TO pump up so much to get a peddle??

That noise, does not sound like a brake pad (or your down to bare metal-which you aren't).

Double check that the anti rattle springs are in properly, again, looking for any shiney parts

With the caliper OFF, is there ANY squeaking when moving?

Can you post a GOOD, LARGE PIC of the assembly W/O the caliper on?.

You also need to look closely for anything nice and shiney, something is metal on metal. We can't see from here..

It very likely will be very small, but there should be something visible.

 

[liamstears]

Thought I better post an update especially as it may help the other poster

My issue in the end was not the disc, the new disc I bought just seemed to mask the problem

In the end I decided to swap out my caliper and mounting bracket as I had suspicions and I was right to do so

When I swapped in the new caliper and mount I put back on the old disc that had the squeak issue and it was perfect

Everything seemed to work a whole lot better everything spun nice and freely, caliper clamped down nice and evenly and most importantly the squeak was gone

Truth be told I cannot 100% pinpoint the issue as I also replaced the rear axle and spacers at the same time (these had some nasty scores etc in them from trying to free them as they were seized) but my best guess after looking at everything is that it was most likely a bent caliper bracket

 

[TownsendsFJR1300]

That, ^^^, is usually what happens. It's VERY EASY to miss that slot and bend the main bracket.

I strongly suspect that bracket is bent, ever so slightly... A good bracket doesn't give much room to the disc...

 

[liamstears]

Exactly, I can see how easily this bracket could be bent too, it only takes 1 previous owner or 1 mechanic not paying enough attention and you could easily not have it lined up correctly and once torqued down I suspect it would bend pretty easy

EDIT: just looked at the vid and pics of poster above, I would defo suggest changing out the bracket and see what happens, over here in the UK I got a bracket and caliper for £25 delivered to my door in very good condition from ebay, can also pick up the brackets off ebay for around £10, gotta be worth a shot

 

[upshiftoverdrive]

Thanks for the help everybody. After taking the bracket I think I may see the rub point. I don't really know why it started doing that? The tab looks straight doesn't it?

Sent from my Nexus 6P using Tapatalk

 

[TownsendsFJR1300]

In the first pic, I suspect, that missing paint on the VERTICAL WELD, (above the tab) is probably just worn from the wheel coming on and off over time..

If you want to take a file and just knock off the top edge of that weld, so it's EVEN with the tab won't hurt.


That, OR, the main bracket WAS INSTALLED ONCE above the tab, scruffed the paint AND BENT the bracket just slightly
(I don't see any marks on the bracket in that area)

 

[upshiftoverdrive]

Is this nub okay to grind down? That weld is actually on the other side of the bracket, so there is no way it is contacting the disc.

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