brakes diagnosis

[DGXSER]

OK, this is a completly new realm for me. 81 xs1100sh, front brakes sticking when cold only. Took off the right front caliper as it seems to be the culprit, found that the pads are worn on about a 15-20 degree angle top to bottom. Wear is even front to back. Mounting bolt seems bent at the top thread area, but not on the shaft section. Is this just poor installation due to the single bolt mounting method?

[prometheus578]

"Believe it or not..."

That's how the pads are for "Specials".
"Standards" have normal lookin' pads... flat... that mount in a secured caliper.
"Specials" have those angled pads... that mount in that pivoting caliper.
The idea sort of was... that when the brakes are applied and the caliper piston pushes on the pads, the high side of the pad makes contact first and the caliper swivvels a little bit.
Looks odd... but that's how it is.

[oldyam80sg]

Yeah the first time i changed the pads i thought something was definitely wrong and bought new pads.The new ones looked the same.That's just how it is.

[tarzan]

The threaded area is the part that keeps the caliper aligned with the wheel.So if you are saying it is bent there,I would get a new bolt.Your pads look about as thick as new to me.

[DGXSER]

Ohhhhh...Thats what that meant.

Now that is somthing wild. I had read on here that they were thicker one side, but I thought that meant front to back, which would also seem wierd. Thanks for the help! I got two new sets of pads coming, so they will be stock for after next season now. Will get two new bolts just to be sure and see if that cures it. The other side is rubbing a little but just enough to cause noise not any noticable friction.

Thanks again for all the great knowledge! These are strange animals in some ways.

[John]

Dragging caliper

Remember to align the right side fork leg to the rotor before tightening up the pinch bolt. You have to align the slot in the fork where the caliper mounts, to the rotor by forcing the right fork leg in or out, then tightening the pinch bolt.

[egsols]

Make sure you have the oring and washer in the right order as well. I usually put a little brake lube inside the spacer too.

[DGXSER]

Well, first I have to source the bolt. Been to all the local hardware and yamaha dealers and no one has one. May have to buy a loger bolt and cut more threads if I can buy a die to fit.

[CatatonicBug]

Plenty of members on here with lot of extra parts for sale. very reasonable too. Don't run out and try to make something that isn't quite right when you can get the exact part for (probably) a lot cheaper here. Just give it a bit, and I'm sure you'll hear from someone with the part(s) you need.

[DGXSER]

thx for the advice Catotonic. I did run otu to a auto parts store and they actually had one that will work I think. It does not have the "Shoulder" but the washer should work for that and it is metric 8.8, is that tough enough for this application, not familiar with the metric ratings.

John, I did not loosen the pinch bolt, al I have removed so far is the caliper. I did rotate the wheel and rotor and watched the gap in the fork guide, it seems to stay pretty consistent and centered.

[bikerphil]

learn about bolts

http://home.jtan.com/~joe/KIAT/kiat_2.htm

[DGXSER]

Fixed

Well, I not only replaced the bolt, but I also found the caliper piston would not push back in, so I rebuilt the caliper (using the existing seals) cleaned all the crud out of the piston, seal ring, the caliper, and the top seal. Put it all back together, bled the brakes out on both sides, then while holding the brake on, tightened the pivot bolt for the caliper and put the top locking nut on. So I think it was a combination of spooge hole, caliper and bolt.

Wheels around like a new bike with only a very slightly noticable sound of pad rubbing (on the side I did not rebuild).

Thanks to TADRacer for the idea of the bolt. And to everyone for your help in diagnosing this and helping me solve it. I plan to find a source for a stronger bolt and replace this one. The original bolt had no marking so it is hard to tell what the strength was.

[TopCatGr58]

Well, I not only replaced the bolt.(snip)
Thanks to TADRacer for the idea of the bolt. And to everyone for your help in diagnosing this and helping me solve it. I plan to find a source for a stronger bolt and replace this one. The original bolt had no marking so it is hard to tell what the strength was.

Hey DGXSER,

According to that bolt guide, the metrick 8.8 is equivalent to a standard 5 grade, which isn't bad at all. And since the OEM one bent, I would think that the grade 5/8.8 would be more than adequate? I looked at the parts fiche but it only describes the part #, no strength grade, so I can't believe that it's that strong of a bolt to begin with!
T.C.

[DGXSER]

TopCat
Yeah, that is what I am thinking now, I looked at the old bolt carefully and it has absolutely no markings on it. Not a number, or a certain number of lines in any pattern, nada. So that must mean it is not of any specific grade or strength and therfore what I got should be equal at least. Just hate to find out I'm wrong by noticing my caliper hanging in the air bouncin off the rotor while I am doin 60 MPH.

[CatatonicBug]

Just hate to find out I'm wrong by noticing my caliper hanging in the air bouncin off the rotor while I am doin 60 MPH.

At least you know that if one caliper falls off, you know you still have the other half of the brake system to rely on!