What is this little brake part called and where can I find it?!

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Jun 4, 2013
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Indianapolis
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1991 ST1100
1991 ST1100 w/o ABS. Working on the left front caliper and noticed the smaller (lower) hex cap screw that holds it to the fork/dampening piston was in a long way. Took it out and found remnants of a hard plastic (not rubber) bushing that apparently a PO had crushed and just kept tightening. I've been on Bike Bandit and Ron Ayers schematics and I don't see it under Forks or Brake Calipers. Hoping someone who has encountered this before may know what they are called and maybe even a part #? Appreciate your thoughts/advice.
Thanks
 
Joined
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'97 ST1100
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1991 ST1100 w/o ABS. Working on the left front caliper and noticed the smaller (lower) hex cap screw that holds it to the fork/dampening piston was in a long way. Took it out and found remnants of a hard plastic (not rubber) bushing that apparently a PO had crushed and just kept tightening. I've been on Bike Bandit and Ron Ayers schematics and I don't see it under Forks or Brake Calipers. Hoping someone who has encountered this before may know what they are called and maybe even a part #? Appreciate your thoughts/advice.
Thanks
If I understand you correctly, what you should have found is a metal bushing that fits into the hole in the anti-dive actuation arm, and the bolt you're referring to tightens against it. I looked at the same fiche pages you did, and I couldn't find it either, which might explain why the PO replaced it with something plastic of similar dimensions, based on your description.

What the part looks like would be best described as a flat washer with a cylindrical barrel attached to it. The I.D. of the barrel is where the bolt fits through, the O.D. of the barrel fits into the hole in the anti-dive rod, and the washer part keeps it secure between the caliper mounting bracket and the anti-dive rod. Not sure what to call it, but you might be able to find one at a fastener supply source.
 
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Does this anti-dive schematic help identify the part(s) in question?
#2 and 3 are the ones tmds3 was referring to in his reply. the collar I'm talking about doesn't show there. Also, I could swear when I take the caliper off and the collar I'm referring to comes out of the anti-dive piston rod, there's nothing left but an empty hole. But the diagram above suggests parts #2 and 3 should be in there on the other side, which I don't recall seeing before, so I'm confused. I'm leaving town first thing in the AM, otherwise I'd pull the caliper and take a picture, but the wife has me packing instead.

edit: confusion solved, see post #10 below.
 
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OP
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Many thanks for the responses! and I believe the problem is solved. The diagram from John Oosterhuis is exactly what I needed, and there is definitely more to the little part than I thought. Agree w dwalby--I think PO put something in there that doesn't belong just to get it down the road (not such a good idea when you are talking about brake parts!) Great to be able to tap into the collective wisdom of the group..Thanks again!!
 

John OoSTerhuis

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There are a couple of anti-dive threads in the ST1100 Suspension sub-forum that may be of interest to you. I recommend the Honda Service Manual if you plan on doing any maintenance on your steed. FWIW
John
 
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looks like tmds3 got his post yanked, presumably because of the link he included in the post, I suspected that might happen.

so here's where its still not looking familiar to me, in the attached caliper diagram bolt 18 goes through the lower part of the caliper bracket, and from what I can remember (bike not in front of me now) it threads into the other side of the caliper bracket as shown in the attachment.

The bolt goes through part #10 on John's anti-dive diagram, and the collar/grommet that I've been referring to fits into the left side of the hole in part #10. I don't recall ever seeing the other two parts that appear to fit into that same hole from the right side, so maybe I'm misunderstanding where those parts are located.

I've had that caliper off the bike at least a dozen times between tire changes and brake pad changes, probably a few more than a dozen, and I just can't line up that exploded parts diagram with my own experience removing and re-installing the parts in question.

edit: confusion solved, see post #10 below.

caliper.jpg
 
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For what's it's worth, I recently found plain old error on the ST1100 (1994) fiche for rear wheel. Did not show O-ring that goes behind splines on driven flange. GL 1500 fiche was correct.
 
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I finally got home and pulled my caliper off, and the parts diagram is making more sense to me now.

I took a closer look into the hole in the anti-dive piston rod, and there is in fact some kind of non-metal collar inside there. It looks like hard plastic, perhaps that's what the OP saw mangled in his. Never noticed that under the brake dust before.

Then I remembered back to the first time I had the caliper off and the little metal collar fell on the ground. I put it back in from the left side, thinking that's where it fell from, but it also fits in from the right side as well. Swapped it around to the right side, put the caliper back on, and it went back together without any issues. So I think I've had it reversed all these years without knowing it.

The final mystery, the little retaining clip, appears to have been missing from mine since I first got the bike, I don't recall ever seeing it, and that probably explains why the collar fell on the floor the first time I pulled the caliper. I'm technically the second owner, but bought the bike when it was two months old with 1,000 miles on it, so the caliper should have been original when I first removed it. The end of the collar protrudes a bit from the piston hole, and appears to align into the hole in the caliper bracket where the bolt goes through. So I'm guessing there's enough tolerance in there for the clip to attach to the collar, and the caliper bracket can still slide over the whole thing and into position to accept the bolt. The collar itself has a machined groove in the end that appears to be where the retaining clip would slide over it, and the groove is pretty thin, so the clip must be too.

So to anyone who has looked at these things lately, do you see the retaining clip in place where I'm describing it?
 
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John OoSTerhuis

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Joined
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Messages
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Location
soCal
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'97 ST1100
STOC #
687
Having recently rebuilt my anti-dive unit I can confirm the clip on the collar, just like the service manual shows.

John
I must have knocked mine off the first time I removed the caliper and either didn't notice it, or found it on the floor and stared at it for a couple minutes and couldn't figure out where it came from. I like these threads, never know when you might learn something new.
 
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