Abnormal front brake pad wear

[northbay]

Hello COG! I just signed up to COG. Sorry about this long post, but I need some seasoned Concours owners to comment on my situation and want to give all the info I can.

I have a 2009 C14 non ABS, owned for a year. Bought new in May 2010, it was a left over model. I have about 11K miles on it. Started hearing metal to metal noise like worn brake pads, but thought no way can this bike have worn pads so soon. Took the pads off and sure enough the outboard pads on the right front caliper were worn to the metal. All of the other pads had lots of mileage left in them. Thought there must be something wrong with the caliper. I was able to push all of the pistons in with my thumb, so they weren't stuck. Went to the dealer to discuss. I never felt dragging brakes or any other brake issues. I've owned lots of bikes and never have seen pads wear out this fast. Service writer asked if I had flushed the brake fluid. I told him no, didn't think that was required on a bike only a year in use. He suggested I flush the brake fluid and put on another set of pads (btw OEM front pads are $140!). I want the problem fixed and don't want to buy $140 pad set only to have them do the same thing. I asked if this was a known issue on the Concours and he said no. I looked in the factory service manual and sure enough it says:

Caliper Fluid Seal Damage
The fluid seal (piston seal) [A] is placed around the piston
to maintain clearance between the pad and the disc. If
the seal is in a poor condition, it could lead the pad to wear
excessively or the brake to drag, which may cause the temperature
of the discs or the brake fluid to increase.
•Replace the fluid seal if it exhibits any of the conditions
listed below.
○Brake fluid leakage around the pad.
○Brakes overheat.
○Considerable difference in inner and outer pad wear.
○Seal and piston are stuck together.


So I'm going to replace all of the piston fluid seals and dust seals and flush the brake fluid and, of course, replace the pads.
My questions are this:
If this is not a known issue, why is it mentioned in the factory service manual?
Have any of you experienced the same issue?
Do you think any of this should be covered under warranty? (from what I've read on forums before, motorcycle warranties are worthless as the dealers just make excuses why your problems are not a warrantied item)

Thanks for your advice / opinions,

northbay

 

[obrienl]

I had about 20 thousand miles on mine before I replaced the pads.  They would have gone another couple of thou but I had a brake pin issue (another story all together).  Some were worn more than others but nothing as drastic as yours.  Could be an issue with a piston seal or brake dust caking around the piston keeping it from retracting after you released the brake lever.  Hard to tell for sure.  I generally replace my fluid as it starts to darken.  Sometimes that is a year, sometimes 6 months.  I also AP brush the pistons about every 5000 miles or whenever I think about it to keep the dust off the pistons.

 

[Fred H.]

I've not heard of this problem on the front brakes myself.

I haven't taken the seals out, but normally they have a square cross section to help bump back the pads when you release the brakes. They should bump back about one or two thousandths of an inch when you release the brakes.

I'd check the return port hole in the master cylinder and make sure it isn't blocked and that the pressure is releasing properly when you release the brakes. I'd also look for any foreign objects (small pebbles etc) around the pad and make sure something didn't get jammed around it.

Were all the pads on that side the same way, or just one? Since each puck has it's own pad, if all the pads were worn on one side, I'd probably suspect it was caused by being pressurized by fluid, and not the seals, since it would be unlikely that all the seals on the same side had the same problem.

A fluid flush is probably a very good place to start, though I'm like you, I'd want to know what really caused it in the first place.

I wonder if a warped rotor could have caused it by rubbing on the pads on every revolution....

If you jack the front end and apply the brakes and then release them, does the front wheel spin freely?

 

[northbay]

There is no issue with plugged return holes in the master cylinder or dragging brakes as I push my bike around frequently in the driveway and garage and would have noticed that sort of thing. When I removed the pads and calipers, no foreign objects were in there. As I stated in the description, the outboard pads on the right front caliper were worn down to the metal. So that would be 2 pads out of the 8 pads used on both front calipers. The other 6 wore about evenly and had a lot of pad left on them. The fact that the service manual states that fluid seal damage can lead to "Considerable difference in inner and outer pad wear" leads me to believe this is the problem. I also believe this is a defect which should be covered under warranty as a one year old bike should not have caliper fluid seal damage. But convincing a dealer will probably be next to impossible.

 

[tjhess74]

im on my third set of pads.  this current set was put on when my new rotors were replaced last summer (10k miles or less on them).  i replaced my fork seals a few weeks ago and noticed my front pads are doing the same thing the op experienced, just not as bad.  the inner (i think) was worn more than the outer.  it wasnt enough to worry about now, but i did find it odd.  one of these days ill clean the calipers real good...

 

[mkorn]

can the pads be swapped around so the worn ones can be put in the place of the less worn ones to get more miles out of the set?
as long as they arent all grooved up that is!

 

[tjhess74]

just off the top of my head, i would say they are interchangable.  there are some that wouldnt due to mating issues.  definately an option.

 

[njdulong]

Hello,
Something I noticed when I replaced my OEM's with EBC's, the slots on the pads that the spring/clip rests in to the left and right of the tab with the hole for the pad pin on the OEM's are not identical so keep that in mind if you swap them around.  I think it has something to do with the spring/clip shape which is different on each end.  Just to confuse things though the slots on the EBC's are identical.  Oh yeah, 2009 ABS.
Later,
Norm

 

[tjhess74]

that would figure!  i just switched over to the oem's from ebc's when the rotors were replaced .  it was worth the thought. thanks for the heads up.

 

[bikermack]

You are not alone, I have the same year and model C14 and had the same problem which started at about the 20K mark (I am now at 32K). I had this issue with two sets of pads and have done all of the cleaning and fluid change type of maintenance. I have stopped short of the fluid seal replacement as I suspect it is pretty expensive (it was on my old Yamaha) and likely not the problem. On this last go around when my right side pads wore to bare metal, I rerouted my stainless steel lines so that the line coming from the master cylinder was outboard and the crossover line was between the master cylinder line and the caliper, a maybe fix at best. All of the things people have said are valid ideas but in my case I believe the culprit was a bent rotor carrier. I have now replaced rotors on both sides with EBC and am using EBC pads. My wheel spins quite freely (rock it back on the center stand and give the front wheel a spin). I looked at the new pads before I wrote this and all are showing even wear. Doesn't take much to tweak your rotor's true and I would check that with a dial gauge as described in the manual or something similar so you can eyeball if the rotor is true. A bent rotor will definitely drag the brake and cause the uneven pad wear.