-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
bleeding rear brakes
- Thread starter xs650dude63
- Start date
xs650dude63
XS650 Addict
Got the piston out, do you think it needs to be replaced, or just need to be cl
eaned up?
Seen worse if this is the bad side but only you can make the call. IF you go ahead, black or white compound on a buffing wheel til there are no sharp edges on the pits. Did you find lots of gunk behind the square rubber seal?
Caliper Piston - Front or Rear - XS650 - 1977-1984
$28.93
IN STOCK
Part
29-0516
Qty
ADD TO MY WISH LIST
EMAIL
Details
Brake Caliper Piston - Fits: Front or Rear Caliper on 1977-84 650's. Replace if pitted or scored or air will seep into the brake system.Length = 41.3mm Bottom Width = 38.15mm Top Width = 27.26mm inside dementions = 5.5mm
Fitment & More Information
Caliper Piston - Front or Rear - XS650 - 1977-1984
$28.93
IN STOCK
Part
29-0516
Qty
ADD TO MY WISH LIST
Details
Brake Caliper Piston - Fits: Front or Rear Caliper on 1977-84 650's. Replace if pitted or scored or air will seep into the brake system.Length = 41.3mm Bottom Width = 38.15mm Top Width = 27.26mm inside dementions = 5.5mm
Fitment & More Information
Last edited:
xs650dude63
XS650 Addict
I did, I scraped it out carefully with a small screw driver.
xs650dude63
XS650 Addict
The other side is clean, the worse corrosion is in the indented part at the top. Do you think I will have any problems if I reuse this one, I will be sure to clean it up real good. What possible problems couldn't I have?
The indented part doesn't really matter. The large smooth area is the brake fluid seal. So that one smaller pit lower in the pic. I buff and use pistons with few small pits but if they are "bad enough" I replace them. Rear prolly isn't as critical as front, unless it's your ONLY brake.
Last edited:
xs650dude63
XS650 Addict
I don't have access to a buffing wheel, do you think I could use super fine sand paper or Emery cloth on the rust pits?
3 or 4" inch buffing wheel about $4 at the farm or hardware store.
The part of the piston that passes over the square o-ring seal is what needs to be in good shape to seal. That big pit on your piston looks to be right about in that area. Like Gary said, up to you if you use it or not. It may not seal real well.
xs650dude63
XS650 Addict
Yeah, why take a chance, if I'm going with new hoses, rebuild kit might as well get a new piston. Thanks, let you know how it goes.
xs650dude63
XS650 Addict
Hey everyone, I got the new parts today, when I install the new piston should I put a little oil on the outside of the piston so it slides back in easier? Thanks
Not oil, brake fluid only. Dot 3 will need to be used.
Only Brake fluid goes in a brake system.
Lube things well with brake fluid only.
Oil will damage the rubber parts.
Causes them to swell up. This can cause the piston to stick, then you will need a new seal.
Leo
Lube things well with brake fluid only.
Oil will damage the rubber parts.
Causes them to swell up. This can cause the piston to stick, then you will need a new seal.
Leo
xs650dude63
XS650 Addict
This part fell off my back brakes, I don't know how to put it back on, any help would be great!
xs650dude63
XS650 Addict
Hey everyone, I got everything back together and I'm still having trouble bleeding the rear brakes, everything is new, everything is tightened down good, i think the push rod, going into the master cylinder is not adjusted right, can someone count the exposed threads on there's so I have an approximate location to where to set the push rod at? Thanks
xs650dude63
XS650 Addict
xs650dude63
XS650 Addict
Or better yet, if someone could take a picture of there's and post it that would be great.
Have you used a mighty vac to pull fluid from the reservoir all the way to the caliper bleeder? Since your MC is a custom conversion, our push rod thread exposure is likely to be different from yours.
This should get you set; loosen the jam nut, then loosen the rod til it wiggles, not touching the piston.. Next adjust the stop bolt (if fitted) so your brake pedal sits where you want it.
If you don't have a stop bolt, the brake pedal will stop against the bottom of the foot peg bracket, that kind of works OK. But the foot pegs are on rubber mounts, so they move when your weight is on them.
OK slowly tighten the push rod until the side play ends, ie the rod end is touching the brake piston. Next; back it off slightly until you can just wiggle the rod a bit. You should be able to feel the rod touch the piston when pressing the foot pedal, Finally; tighten the jam nut and recheck for just a little slack. I don't have a disk rear shop manual but this should be the correct setting.
This should get you set; loosen the jam nut, then loosen the rod til it wiggles, not touching the piston.. Next adjust the stop bolt (if fitted) so your brake pedal sits where you want it.
If you don't have a stop bolt, the brake pedal will stop against the bottom of the foot peg bracket, that kind of works OK. But the foot pegs are on rubber mounts, so they move when your weight is on them.
OK slowly tighten the push rod until the side play ends, ie the rod end is touching the brake piston. Next; back it off slightly until you can just wiggle the rod a bit. You should be able to feel the rod touch the piston when pressing the foot pedal, Finally; tighten the jam nut and recheck for just a little slack. I don't have a disk rear shop manual but this should be the correct setting.
Last edited:
