| Author | Message | ||
     Bleblanc03 |
I am very confused about a mysterious o-ring in the assembly diagram/service instructions for the Nissin ZTL 6-piston caliper on my 2003 XB9S.  This assembly diagram for the front caliper shows a "small o-ring" (item #8) that looks to me as if it goes in/around the hole where the caliper fastener (of which there are 4).  The directions for reassembly tell me to replace these "small o-rings". Are these, in fact, meant to sit btwn the two halves of the caliper on the 4 caliper fastener bolts? They weren't there when I took my caliper apart, but I bought the bike quite used, so that didn't surprise me. The problem is, no service tech/parts dep't/H-D customer service person either knows of this o-ring or can supply me with a part number. I bought some 5/16" dia. x 1/32"(?) thick o-rings from a hardware store and fitted them. I put the caliper back together (wary of the connection where fluid passes through) with one of these o-rings on each caliper fastener bolt. The brakes work marvelously, but each time I check (~6-8 hours), there is one bead of brake fluid hanging in tension from the bottom of the caliper. Please advise. Thank you. | ||
| Gowindward |
My guess is that there are fluid passages from outside of the caliper (The side the brake line feeds) to the inner side of the caliper. There would be o-ring seals at those locations and not at the bolts that hold the caliper together. | ||
| Bleblanc03 |
There is a passage at the top of the caliper, which is what I was referring to when I said I was "wary of the connection where fluid passes through." This passage consists of a rubber piece on each side that seat together (tightly) when the halves are bolted. But I saw no o-ring there to be replaced. | ||
| Gowindward |
If you have o-rings on the bolts holding the caliper halves together, they made be creating enough space between the two halves to keep that passage from sealing completely. Try removing the oil rings you added and put in all back together and see if the leak stops. The Parts Catalog does not show the #8 o-ring in the illustration in it as seen in your service manual image. | ||
| Bleblanc03 |
Yeah, that's where I felt the fluid was coming from. I just am so confused by that diagram/instruction as far as the #8 o-rings.  _ I figured maybe Buell/Nissin had some even skinnier o-rings than I could find. Ah, well, I guess it's back apart for the caliper tonight. | ||
| Puddlepirate |
That o-ring comes in the caliper rebuild kit. I don't believe you can buy them separate. I'm in the process of rebuilding mine as I type. You may be able to get a round one from the hardware store to fit, but it wouldn't be the proper one. $25-ish is how much the rebuild kit cost me from Surdyke. It would be cheap insurance for you. Since those metal surfaces don't seal well by themselves, you would be seriously screwed if your leak rate increased and then you tried to brake. |
