Post by bradshaw106 on Jan 30, 2010 6:24:32 GMT -5
I have a 79 xs with discs front and rear. How do I get my bike to stop again? You can mash on the pedals and the bike will slow, but If I had to do an emergency stop i would be dead. I put new pads in the rear but that did nothing. I don't even know where to begin. I was thinking updated master cylinders??
You should get the front ones working first, they are important. Does the lever pull in all the way to the handgrip or does it stop halfway? If it stops before it reaches the handgrip, the piston in the caliper may be seized or the bolt with the rubber cover at the caliper may need freeing up. If the lever pulls all the way to the handgrip you have air, a leak, bad master cylinder, or something else bad.
Life in the slow lane, sure to make you lose your mind.
Since my brakes also are horrible, I'll be watching this thread. I know brakes. I have a new master cylinder, lever, brake line and fluid in the front, only the caliper, disc and pads are original. Everything works just fine, the line has been bled, except the stopping power is way weak. The only thing I can think of is that the pads are glazed. Pad thickness is okay, I have not looked at the surfaces. I've ridden another XS650, so I know my brakes are not normal. The rear brake also sucks, once again, everything is there and working, but in my case the rear is a drum. Once again, I'm thinking glazed shoes?
Post by bradshaw106 on Jan 30, 2010 7:32:17 GMT -5
My bike sat for a long time. when I got it flushed the brake fluid front and rear and bled the systems. To the best of my knowledge I have full travel of both front and rear levers. defiantly feels spongy in the front but I bled the air...... maybe an updated master cylider could be just old. Im hoping it's not my rotors I heard you cant turn them.
yfrog.com/5cimag0191jjyfrog.com/jvimag0195j One side of the caliper moves on the bush under the rubber, when the piston pushes on the disc it draws the other side on to the disc. If the bush is not able to move inside the rubber it wont let the two pads clamp on the disc. It needs to be clean and at least have some wd40 on it. The pictures are a left side brake.
Last Edit: Jun 2, 2010 6:49:13 GMT -5 by slow rider
Life in the slow lane, sure to make you lose your mind.
Bleeding the brakes on the XS650 is one of the real challenges that we all have to master. It's almost like a right of passage. If you get it right, you can tell the tale to all your motorcycle buddies over a cold beer.
1. The conventional bleeding method is just a starter, so do that first. 2. The results from #1 will not be satisfactory. The lever will still be spongy no matter how long you try. 3. Try removing the caliper. Turn it so the piston is facing the floor. Alternatively press the piston into the caliper (very gently)followed by gently pumping the lever to push the piston back out. Watch for the air bubbles in the reservoir. Do this until your arms hurt. 4. Or...get a vacuum pump type bleeder and suck the fluid and all the air bubbles out while continuously adding fluid to keep the reservoir full..
Last Edit: Jan 30, 2010 8:05:18 GMT -5 by pamcopete
A couple of things to note here. When lubing the bushing under the rubber sleeve, use disc brake lubricant, and be sure the sleeve is still flexible. If it's lost flexibility, replace it. If you're deglazing pads, use a piece of medium garnet paper (woodworking sandpaper) or medium Scotchbrite (the type for use with metals) taped down on a known-flat surface such as a bit of plate glass. Move the pad on it in a figure 8. Don't use wet-or-dry paper, as it'll leave metallic residue. Use the same abrasives on the rotor, wiping down with acetone as you work. Then do a fresh break-in on the components. It take very little to deglaze pads, and the rotor cleanup should be done whenever new pads are installed. Breaking glaze on a rotor is another story. It can be done by hand if you have a couple of days to devote to it, but replacement is a more practical idea. If you know what you're doing rotor glaze can be broken with a ball hone.
Re. lines, the longest manufacturer's service interval I know of for rubber lines is 4 years. Flexing lines yield mushy action. Braided stainless lines last indefinitely and don't flex.
Re. bleeding, unscrew the brake line junction block from the lower clamp so that you can tweak it closer to the vertical and allow air to rise out of it instead of being trapped, and reposition the master cylinder assembly and turn the bars so that the cylinder is angled a bit upward toward the reservoir, allowing air to rise. Remove the MC top, pump the lever till you see not bubbles rising, give the line a few wiggles, replace the cap, tie back the lever, and go away for a few hours. Repeat if needed. When you have pressure, attach a piece of clear vinyl hose to the bleeder valve on the caliper, and run the hose into a bottle. Apply light pressure to the brake lever, at the same time opening the valve just enough for the pressure to release. Close the valve just before the lever bottoms. Keep an eye on fluid level in the MC. This is a fine opportunity to replace the old fluid.
With the OEM floating caliper, using an 11 mm. MC will provide more force per pound of pull than the OEM 14 m.; not recommended for use with rubber line. Ferodo Platinum pads are a big improvement over OEM. Following Michael Morse's advice, I'm currently using a pair of his Vesrah sintered pads. Rotors won't last forever with those, but they're very effective.
Last Edit: Jan 30, 2010 10:26:05 GMT -5 by grizld1
r80rt: :)This is a splendid write up, THANK YOU!!!!
Dec 26, 2015 16:54:05 GMT -5
mashermoto: What the what is this shoutbox for? Or should I shout, WHAT THE WHAT IS THIS SHOUTBOX FOR!
May 12, 2016 22:22:21 GMT -5
motormike: Good Day ...just a FYI.. Wild Cat is this Labor Day weekend. Still go'n on. A few 650's still make the scene. Various rides at different skill levels each day.. awards dinner sunday eve. BS in the park'n lot after dinner.
Aug 23, 2016 7:57:01 GMT -5
lsettle: First post in over 6 years!
Aug 28, 2016 19:45:17 GMT -5
kardon: Wow quiet here, where did they all go.
Oct 7, 2016 2:18:13 GMT -5
gggGary: XS650.com LOL
Feb 16, 2017 20:49:02 GMT -5
buell88: Anybody have any idea who built the xs650 tracker used in the Draggin Jeans Ad on Pipeburn?
May 16, 2017 16:24:09 GMT -5
joshua: The regulator/rectifier unit I got from Mikes PMA has closer hole spacing than original. Are we supposed to mill the holes to fit?
Jun 7, 2017 19:25:58 GMT -5
joshua: My bad. I found the bracket they supplied to mount the rectifier/regulator... Uh oh. How is this meant to work? Which way is it meant to mount? Looks like I have to use some spacers or something. Good instructions would be nice.
Jun 7, 2017 22:09:52 GMT -5
craig8johnson: Not sure if this is the right spot or not but oh well...
Jul 11, 2017 18:04:15 GMT -5
craig8johnson: I'm checking the charging system. I'm afraid I might have fried the last battery. With the solid state regulator (after market) what should it be charging at. The book says, I think, 15 volts. I'm hitting 17 when revved. Is that too high?
Jul 11, 2017 18:06:19 GMT -5
gggGary: Yes 17 volts is too high, about 14 volts is max, sounds like you don't have the right regulator or it's wired wrong.
Jul 13, 2017 6:54:33 GMT -5
dean: Just saying Hello, new member who is going to fix up a 79 XS650 that has seen its better days. I will definitely have lots of questions coming up.
Jun 23, 2018 16:45:32 GMT -5
tt650: Trying to breathe life into a 1980 that's been stored (indoors) for 25 yrs. Air filters are dry rotted. Have cleaned carbs but she only runs briefly on choke then stops. Need jet setting info and other ideas that might help her idle and rev.
Jul 3, 2018 19:15:19 GMT -5
trix13: Hey everyone! New to the forum and am fighting those gremlins!! New charging system, ignition switch, coil and fuse box. Resistance is higher than normal on the ignition pick up so I'm trying to find one. No such luck yet.
Aug 16, 2018 8:50:48 GMT -5
trix13: Also, even though all of my connections are clean, I cannot seem to find out why , when at higher rpms, I hit the signals and the rpms pulse with the signals...hahah. same with the brake light. I appreciate all input!!
Aug 16, 2018 8:55:08 GMT -5
bob99: how do I post a question. I am new to the forum
Jun 6, 2019 10:52:10 GMT -5
adlpc: Hello all! Been enjoying your edifying posts and discussions - and as a fan of the XS650 since my early teenage years happy that I now own a 1980 Special which I plan to turn into a vintage half faired racer. Thank you all for being here!
Oct 1, 2019 0:58:56 GMT -5
jimothyj: Hello everyone, I just joined & wish would have known about this site in 2014 when I brought my 1974 TX650A back from the grave. I have spent a good deal of $$ and alot of time on it. Just painted it and working on electrical, I will post pics soon,
Apr 10, 2021 2:14:13 GMT -5
louisvan: trix13 - I had a problem with my 1975 SX650. When I got to highway speeds, the engine lost power. The problem was in the connectors. At a certain vibration and the wind pushing on the wiring loom, the connector lost continuity. A bad crimp to the wire.
May 20, 2021 1:19:09 GMT -5