Front brake: pad guide rubbing on rotor (pic included)

[thomasbien]

After hearing a "swooshing" noise from the front brake of my 1996 GS I took the caliper apart and had a look.  Nothing obvious but I decided to replace the pads.  After a thorough cleaning of the caliper and installation of the new pads I put it back together.  The noise was still there.

Tonight I laid on my back, looked up at the outside pad from below as I spun the front wheel.  It looked as though the pad guide clip and what I will call pad retaining nub were very close to the rotor.  After marking the retaining nub with some nail polish I spun the wheel again and found the nail polish was gone.

See the following picture.  The witness marks on the pad guide clip and retaining nub are pretty obvious.



So how does this happen?  The pieces showing contact are attached to the caliper slider which is bolted to the front fork.  This piece does not move relative to the rotor.  I do not understand why these pieces are contacting the rotor. 

The end of last year I had the front tire replaced at the local dealer, so of course they removed the front wheel and reassembled.  Could something be out of position with the front wheel assembly to cause the fork and therefore slider to be closer to the rotor?  This is the first I have ridden the back since the winter and I reallly do not remember this sound from last year.

My first idea was to file down the retaining nub but I would not be able to do that to the guide clip.  I'm open for suggestions.  I almost forgot to add... I measured the runout of the rotor with a dial indicator and found it to be approximately 0.240mm which is less than the 0.3mm max spec.

Does anyone have some insight or experience with a similar issue?

[ducati_nolan]

Check to see if the wheel is centered between the forks. If one of the wheel spacers got screwed up it could put the wheel off center.

I'd avoid grinding, the thing should work and you have a problem somewhere else.

Try spacing the wheel and/or caliper with washers.

[Wrecent_Wryder]

5=d

[thomasbien]

Thanks for the quick replies.

Wrecent_Wryder: I had found that post last week and actually replied to gsJack with a question.  The rotor wear he was experiencing was at a radius closer to the axle on the rotor than what I am experiencing.

ducati_nolan: I agree the root cause of the problem is not the caliper per se.  Looking at the pictures of the wheel spacer and axle spacer in the Haynes manual cause me to also wonder if the wheel is centered between the forks.  Check out this picture:



What do you think about the exposed "shoulder" in the red circle?  Comparing to picture 14.4a in the Haynes manual it looks to me like the axle spacer is protruding on my bike.  Does anyone else notice the same protrusion on their machine?

I think I will take these couple pictures and the Haynes manual to the dealer tomorrow and see what they think about their front wheel removal and tire change.  That should be an interesting visit.

[gsJack]

Loosen the clamp screw at the bottom of the right hand fork and bounce the front end down and up a few times and then retighten that clamp screw.  You can see the line on that sleeve between the light and dark area, the light part should be inside the fork clamp.  That adjustment allows for the tolerance stackup in the assembly of the parts.  Once that is adjusted properly you can take off the wheel and put it back on without loosening that clamp and sleeve.

It's unusual for that sleeve to be sticking out of the right fork leg that far, make sure the stop lug on the speedo drive on the other side isn't caught up behind the left fork leg holding the whole wheel assembly over to the right out of place.  The lug should be just behing the fork leg and just touching it from the backside.

[thomasbien]

Helpful suggestion gsJack!  I made my last trip to the garage for the night and did as you recommended.  However, the sleeve did not move after I loosened the clamp screw and bounced the front end.  So I held the right fork with one hand and tapped the axle with a rubber mallet.  Now the axle space is almost but not quite flush with the fork clamp. 

More importantly, I put the caliper back on and... no more metal to metal swooshing sound!  As a matter of fact when I lay on my back and look up at the underside of the caliper I can see a several millimeter gap between the retaining nub and pad.

I am still going to stop in and talk to the dealer about this tomorrow.

This is an extremely helpful forum, thanks to those of you that make it this way!

[ben2go]

If your brakes had failed or you would have had any kind of an accident,
you could have owned that dealership.An then you could fire the dumb
ass that f@@k up your bike.I and many others am glad that you found
the error before it led to an accident.
Happy Trails.
Ben

[pbureau69]

I had this issue some times back after changing my front tire, could not get it to get centered, brought it to a local yamaha dealer (live in the country side and these guys are great and work on all bikes alike from harley to suzuki) took teh tech 15 mins, he said I assembled it correctly, he just removed it all and reassembled it back and bounced it  and it was straight again... he did not charge me (lucky I guess they are really nice guys).... Jack is prolly right.

[thomasbien]

Stopped into the dealership and visited the service manager today.  I calmly and politely explained the issue beginning with having a new tire installed last year and ending with my discovery of the contact with the rotor last night.  I also showed him the three pictures that are included in previous posts (I had printed them and took them with me).

The service manager listened to my story and then grabbed a mechanic to go out and look at my bike with me.  They agreed with our assessment and the service manager said "we are going to replace that rotor".  Now the rotor is on order and will be installed with no charge to me.  The service manager actually thanked me for being patient and not getting upset like other customers have done.

It is a quality shop and I figure the mechanic just made an oversight that day.  In the end they are making it right.

Thanks again for the help!

[ohgood]

Stopped into the dealership and visited the service manager today.  I calmly and politely explained the issue beginning with having a new tire installed last year and ending with my discovery of the contact with the rotor last night.  I also showed him the three pictures that are included in previous posts (I had printed them and took them with me).

The service manager listened to my story and then grabbed a mechanic to go out and look at my bike with me.  They agreed with our assessment and the service manager said "we are going to replace that rotor".  Now the rotor is on order and will be installed with no charge to me.  The service manager actually thanked me for being patient and not getting upset like other customers have done.

It is a quality shop and I figure the mechanic just made an oversight that day.  In the end they are making it right.

Thanks again for the help!

Dude, IMHO that's a stealership that deservers a little free advertising. Not to mention the service manager, and mechanics' first names at least. If they ever stumble across your thread, they'll really enjoy the kudos.

Congrats on finding a GOOD stealership to parton.