brake calilper piston postioning

[scotto]

Hi Guys, probably a dopey questions but...

Recently acquired XS and first pull-down of rear caliper found that the piston as positioned with the hollow end pressing against the pad. Parts diagrams do not have the resolution for me to confirm if this is the way they are supposed to go, but it doesn't seem right to me.

Q1. Surely the hollow is supposed to be positioned so that it fills with fluid?

Q2. This rear caliper is bit pitted in bore and piston. I am guessing that NOS calipers are rare as hens teeth. Has anyone found success in getting this calipers reconditioned with rebore and new pistons? Is this the way to go? Does it matter much?

Any help much appreciated.
Scott J
Cairns, Aus

[trbig]

The hollow end does in fact face out. The fluid pushes on the back side and reduces the amount of fluid needed. You can usually clean up the piston with some fine sand paper. As long as they don't leak, a few light pits won't hurt it. If you do want new, they are available here at Partsnmore.com



Welcome to the site!! And let me be the first to say...

PICTURES, man PICTURES!


Tod

[John]

The positioning of the pistons is correct. Hollow side out. The rear pistons can be had at mikesxs.com. It is the same as the rear piston on the xs650 Specials of the same vintage. You may be able to source a used one somewhere if the 650's were common in your area.

[red bandit]

Hollow end of piston goes toward pads. Pits in caliper shouldn't hurt as long as not extreme. Pits in piston??? Depends how big/deep. Maybe hone the caliper and 400-600 sand paper on piston. Try it. If it leaks, needs repacement.

[TopCatGr58]

Hey Scotto,

Take a look at this thread , it has some photos of the calipers and pistons, and rubber O-ring and info about cleaning and reassembly. You'll have to click on each photo to see the full size image, Photodump changed their posting format!
T.C.