i need front cal piston

[redbone]

i need a front caliper piston for 1980 mns xs1100. ..yes...i tried to reuse the old one that was "pretty good". yep, its leakin. anyone know a site or have one in like new condition let me know. tx, redbone:

[XSPastor]

Hmmmmm...
That is a tough one. I did some searching and haven't found anything new yet, but one site had the same rebuild kit for the front of all these bikes:

XJ 650 MAXIM '80-'83
XS750SE/SF SPECIAL '78-'79
XV750H/J/K VIRAGO '81-'83
XV750MK MIDNIGHT VIRAGO '83
XS850LG/LH MIDNIGHT SPECIAL '80-'81
XS850SG/SH SPECIAL '80-'81
XV920 VIRAGO '83
XV920 MIDNIGHT VIRAGO '83
XS1100LG MIDNIGHT SPECIAL '80
XS1100SF/SG/SH SPECIAL '79-'81

Maybe you can find a piston for one of the above and use it in your bike. One assumption that I am making that may not be good is that all the pistons for these bikes are the same diameter and length. Same rebuild kit doesn't always mean the same piston size. Anyway, this gives you someplace to start. I'll bet a group member has one that you could buy. Andreas should be able to help you out.

FYI, This was the site: http://crc2onlinecatalog.com/caliper...its.htm#YAMAHA

[XSPastor]

MikesXS Part #29-0516 might be the right one. You'd have to measure yours and call them to check the measurements on the one they sell.

[oldyam80sg]

I have a caliper that came off of my 80SG if you need it.You're more than welcome to examine it.My calipers were sticking and i ride with one caliper and stainless lines.Piston should be in decent shape.

[TopCatGr58]

Hey Redbone and Pastor,

The 80MNS uses the same swivel calipers as the regular 80-81Specials. The 79Special lists a different part # for the entire caliper assembly!?

The MikesXS pistons will NOT WORK, they are the same as the STANDARD's front and rear, as well as the Specials REAR calipers, but not the same as the Specials Swivel fronts!!

The 81MNS uses the same calipers as the 82XJ's fronts, and they are essentially unobtainium!

I checked out several of the bikes listed by Pastor that use the same seal kit, and several of them use the same "STYLE" of swivel caliper like the 80-81 Specials, and in the later models, Yamaha breaks down the caliper parts to INCLUDE a piston/seal combo kit.

And according to www.cycle-parts.com
the kit 2G2-W0057-00-00 is still available at $43.82, which has a piston and seal kit combo. BUT I can't state whether this piston is really the same size as the 80-81 Specials??

These are the official part #s for the ENTIRE caliper assemblies:

80 XS11 MNS: 3J6-25810-02-00
81 XS11 Spec: 3J6-25810-02-00
Seal Kit: 2G2-W0047-00-00

81XJ650 4H7-25810-11-00 CALIPER ASS'Y (LEFT)
82XJ650 4H7-25810-11-00 CALIPER ASS'Y (LEFT)
Seal Kit:2G2-W0047-00-00

I wonder if anybody has either an 81-82XJ650 Maxim,
or an 83XV920 with the swivel front calipers, that could take the pistons out and either measure them, or compare them to the 80-81 Specials??
T.C.

[Bigleo]

piston

Hi, I've had good luck repairing corroded pistons. Usually the corrosion is worst in the seal groove in the piston. The minor corrosion on the piston sides is usually easily removed with oil and 400 grit wet or dry sandpaper. I then protect the piston with duct tape, leaving the seal groove exposed. A quick glass bead blasting then cleans out the groove, and also the inside of the piston if desired, leaving it looking like new. 400 grit sandpaper also cleans up the caliper bore, and if the seal groove in the caliper is badly corroded, it can be bead blasted at low PSI, say 50lbs, and it will clean up nicely. I did this to all three of my calipers, 8 years ago, and still no leaks. Also make sure you use a generous amount rubber grease on assembly, I believe this helps inhibit further corrosion. I always change my brake fluid every year, with Ford brake fluid. It supposedly has the most moisture neutralization capabilies.
good luck
Leo

[fredintoon]

Hi Redbone,
sorry, CRS has kicked in and I can't remember which way round the seal goes and Clymer's most carefully don't show a clear picture but what's important is this:-
All three surfaces of the seal groove plus the cylindrical surface the remaining face of the seal moves on/in have to to shine like an outhouse door on a frosty morning. So long as the piston moves in the caliper nicely the surface finish on other parts don't matter. Use a Dremel tool, brake hone, thin strip of emery tape etc. as appropriate to clean up the surfaces.