Rear brake issue

[RainCityRider]

Hi all,

Put new rear pads on my 07. After reinstalling the caliper the rear brake hardly slows the bike. I changed the fluid with super blue and bled the caliper.

The issue remained. I have strange pad wear as well. Not sure what's going on.

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[TownsendsFJR1300]

Third picture down

Your brake caliper mount SLOT is IN-CORRECTLY ATOP the swing arm, NOT in the swing arm pin-


***It is also VERY POSSIBLE that the main aluminum bracket is now bent as the axle is seen as tightened down.

Put that bracket back on correctly and start taking some measurements... To see if its straight or now junk...

If that bracket WAS installed that way for sometime, its KEEPING the caliper from mounting square to the disc, at an angle (thus the un-even wear). That alone will limitt a good part of the pad contact the disc, nor pump up hard...That is DEFINITELY PART of the issue NOW....


Keep reading as you have other issues:

Looks like for the un-even wear, the brake calipers were NOT floating / centering themselves, thus the un-even wear.

Those black rubber boots have to be cleaned out once in awhile and re-greased with brake specific grease. I suspect one or both
of those main mounting bolts / holes are pretty gooed up.

The piston in the pic looks pretty nasty as well. Its very possible that when you pushed the piston back into the bore, grit went along with it and is now jambing up.
You may have cleaned the piston very well, but if you didn't pump it out a bunch, I'm sure there's still grit in there.

With the un-even wear, the nastiness of the caliper and no brakes to speak of now, IMO, buy a new seal kit(super cheap, about $10.00 and not hard to do).
Disassemble the caliper, boots, etc spotless. Clean up the piston (or replace if pitted), new seals, grease those boots, etc , bleed and re-assemble.

 

[RainCityRider]

Unfortunately this is my own doing. You are saying the bracket is in the incorrect location. How does it mount correctly? I need to disassemble and rotate the bracket clockwise to fit a groove on the swing arm?

I will replace the seals and check the pistons too.

Is the uneven wear a symptom of the bracket mounted incorrectly or another issue? I did grease the pins when I did the pads.

Hopefully the bracket is still straight. I feel a bit silly. I've been riding it like this for a little while now.




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[Ben sIII]

How does it mount correctly? I need to disassemble and rotate the bracket clockwise to fit a groove on the swing arm?

That's it exactly. take off the rear wheel and look at the swing arm and the channel in the bracket and it will all make sense.

But i concur with above, looks like the caliper isn't floating, check that the caliper can slide on the bolt. and probably get some new pads.

 

[TownsendsFJR1300]

Appreciate the honesty, stuff happens....

But yes, as posted above a little clearer, there's a elongated "slot" on the inside of the swing-arm (see below circle)

We did have a member with a bent mount so it does happen... I'd put it back together correctly, pump it up and see if the brake will get hard and if the pads seem to seat squarely to the disc. If not, that parts bent and needs replacement.

IMO, I would still do the other brake maintenance, BUT the above is your MAIN issue...


Here's a pic, I circled the "Tab":
Make sure both are clean so when adjusting the chain, there's no binding. It should slide forward and back easily.





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[TownsendsFJR1300]

Were you able to re-set the bracket Raincity?

Any up dates?

 

[RainCityRider]

Yep, I pulled the axle and put the bracket in the correct position. The brake now functions but its performance is somewhat poor I think in part to do with the pads being worn so unevenly. I ordered new pads and seals.

The bracket appears straight but it's hard to verify since I never examined it closely before.

As a side note does anyone know how many seal kits the front calipers take? Thought I might do them all at the same time.

 

[TownsendsFJR1300]

Yep, I pulled the axle and put the bracket in the correct position. The brake now functions but its performance is somewhat poor I think in part to do with the pads being worn so unevenly. I ordered new pads and seals.

The bracket appears straight but it's hard to verify since I never examined it closely before.

As a side note does anyone know how many seal kits the front calipers take? Thought I might do them all at the same time.

You could slip the rear caliper on (cleaned up some), with the NEW pads. Peek and see if their pretty much sitting up against the disc properly,flat (no angles)..



For the fronts, I believe it take TWO kits, Call Partzilla (or who ever before ordering to confirm). My fronts were around $80 delivered a couple of years ago (around $100 now).

As a side note, its MUCH easier, for the fronts, to have a small air compressor (capable of 100 PSI) to blow the pistons out, (the hardest part).

Use a pointy "blower" with a short piece of rubber hose cut at an angle to get into the tight orifice to blow out each piston. And put a rag in there as they will fly and /or pinch a finger..


.

 

[RainCityRider]

So I replaced the pads and seals after my mix up. The brake works now but is still very spongy and unresponsive. A hard press of the pedal slows the bike marginally.

The pads sit flush and I bled the system well. Could the master need rebuilding?

 

[TownsendsFJR1300]

It's very rare the rear master goes bad (of course it's possible but not likely).

It sounds like there's still air in the system however in your case, that brake
bracket may very well be bent not allowing the caliper/pads to sit dead nuts on / crooked

Can you get a hard brake pedal while stationary, on the center-stand after bleeding?

**If you loosen the axle fully & loosen the mounting bolts and bleed (don't ride obviously) and bleed, can you get a firm pedal?(we're trying to make sure the caliper DOES sit properly to the disc). If so, the bracket would be bent. It is VERY possible that bracket is bent.


Are you using a Mity vac (or similar), or bleeding manually?
The rear brake usually bleeds out very easily(much easier than the front).


Lastly, from your very first post:
"Put new rear pads on my 07. After reinstalling the caliper the rear brake hardly slows the bike."

Was the brake bracket removed too? (not just the pads) . I'm trying to determine when you last had a solid brake, (before or after the brake bracket was installed improperly)

 

[RainCityRider]

I'll check those suggestions. The bracket looked straight but I'll test. I last had a solid pedal before improperly mounting the bracket. I'm bleeding manually at the moment.


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[TownsendsFJR1300]

I'll check those suggestions. The bracket looked straight but I'll test. I last had a solid pedal before improperly mounting the bracket. I'm bleeding manually at the moment.

I think you just posted the answer above...

Remember, that axle is tightened down to 87Ft lbs. Put that much torque on an aluminum part and somethings going to move(bend)

PM Scooter65 and or put out a wanted to buy ad. He's always parting out bikes and there's lots of spare
used parts about.

If not buying new, I'd buy from a known member here vs possibly getting burnt on Flea Bay..

 

[RainCityRider]

Sorry, did I answer your question? Brakes worked okay to begin with, replaced pads while wheel was off, put bracket on incorrectly and had no brake. Fixed bracket issue but pads had been unevenly worn in the meantime. Finally replaced pads and seals, bled the system and have maybe 80% of the original brake feel.

 

[TownsendsFJR1300]

Sorry, did I answer your question?

Yes you did, from the above "I last had a solid pedal before improperly mounting the bracket.".

IE, that bracket sounds as if it's tweaked / bent just slightly now..

 

[RainCityRider]

Remember, that axle is tightened down to 87Ft lbs. Put that much torque on an aluminum part and somethings going to move(bend)

I agree that the bracket could be tweaked but why would tightening the axle bolt apply a torque on the caliper bracket?

 

[TownsendsFJR1300]

Because the bracket wasn't seated (no pressure when in the slot),

However, yours wasn't seated correctly and when tightened down, something had to give / bend.

IE, The TAB was pushing up against the bracket, instead of the two, fitting inside each other..

Doesn't sound like much but when you add in how much run out is allowed in the disc, etc, it doesn't take much.

 

[RainCityRider]

Ah, I see what you are thinking. I thought that you meant the act of tightening the bolt torqued the bracket, you are saying that compressing the tab by tightening the bolt put a force on the bracket. When I put the wheel on I for some reason was thinking that when the brake was applied the caliper would try and rotate forwards and that the tab would hold it against the top of the swingarm.

I believe that when I assembled it like this the bracket was still able to rotate a bit about the axle.

I certainly could have still tweaked the bracket in another way.

 

[TownsendsFJR1300]

Ah, I see what you are thinking. I thought that you meant the act of tightening the bolt torqued the bracket, you are saying that compressing the tab by tightening the bolt put a force on the bracket. When I put the wheel on I for some reason was thinking that when the brake was applied the caliper would try and rotate forwards and that the tab would hold it against the top of the swingarm.

I believe that when I assembled it like this the bracket was still able to rotate a bit about the axle.

I certainly could have still tweaked the bracket in another way.

Yep, exactly. If you can't get 100% of your braking as before, that's the only thing left.

Now had you tightened the axle with the bracket more more rotated, CC just a tad (with NO side load), and it later rotated
it'd be way less likely to bend.

 

[RainCityRider]

Yep, exactly. If you can't get 100% of your braking as before, that's the only thing left.

Now had you tightened the axle with the bracket more more rotated, CC just a tad (with NO side load), and it later rotated
it'd be way less likely to bend.

I did, which is why I'm curious as to how it became tweaked. I'll update this weekend after I take another look at it. The list of things to do to the bike is piling up quickly.

Can't wait to get my R6 forks and S1 headers on!

 

[TownsendsFJR1300]

So the bracket IS bent?


http://www.600riders.com/forum/bikes-parts-wanted/57607-rear-brake-caliper-bracket.html