I have a '80 XS650 Special. I have completely rebuilt my front brakes. New master cylinder, new caliper, new pads. I am having a problem with pressure building and not allowing the caliper to retract, gradually locking up the front brake. If I open the bleed valve, it releases the pressure and then it is OK for a while. I'm pretty sure that the vent hole in the master cylinder is open since it's brand new and all of the fluid is fresh since the rebuild. The only thing left that I can think of are the hoses. I've had a bad hose lock up a caliper on a car so I am inclined to go ahead and replace them. Before I replace them, does anyone have a suggestion of other things to check?
I think you have the bases covered--lines or MC. Every Japanese factory manual I've ever seen, old or new, specifies service life for rubber brake lines as 4 years, so those old lines need to go anyway. But don't assume that the MC doesn't have issues because it's new; where was it bought, and who was the vendor?
Thanks, I will check out the MC while I have everything apart to replace the lines. In looking at the lines, it looks like it would make sense to replace the two lines and the connector under the headlight with a single stainless steel line. Is there any reason not to do that? Do you know the correct length and do you know a good source?
A one-piece stainless line is the way to go. I drop mine through a standoff on a lower fork clamp bolt and another standoff on the fender. 5twins uses a longer line and runs it through the OE routing, securing it to the center of the lower fork clamp where the junction block for the old lines used to live. I use a Russell universal line. To measure, jack up the front end so that the wheel hangs free and run a piece of plastic tubing through the path you want to use. Allow a little slack to be sure you don't stress a line if the forks top out.
..... the caliper bolts to the bottom of the bracket.... there's a slide inside the rubber boot..sometimes it sticks.. which will cause a drag'n caliper. I always press the side out..even on new units... a heavy thumb does the deed if it's not frozen... then I lube the inside with brake grease.. Brake.. not standard bearing grease... the small ends of the rubber cover for the slide I also fill with brake grease.. this help the caliper slide and also helps keep condensation from form'n and it's related rust issues... this may not be your problem but is worth the time. I have seen hoses go bad..one Xs and a few cars. Usually someone clamps the hose too tight to service the caliper.... prevent fluid drain... and it forms a internal flap.. a one way valve much like the four in yer heart... brake fluid can't flow back after the lever has been released,
70',82' Xs650, 65' Tri 650 Tiger, 70' 450 Ducati "Jupiter", 1970 350 Ducati,66' Triton (featherbed frame) w/73' 750 Tri engine, 68' Honda 450P (Police),75' "CONDOR"(Swiss Army), 29' Motobecane (French), 50' & 52' Terrot Paris Police m/c's, 54' Peugeot French Military Police m/c.. Algerian veteran. 50' Alycon French fire bike, 82' Cx500 Police trike (Ex Chicago Police 2011 R/Enfield, with sidecar, 06' Helix, 62' Cushman, 71' Guzzi Ambassador, 65' Ford Mustang, 04' Mustang convertible.. 1 wife
As mentioned, I use a small homemade strap bracket attached to the lower triple tree for a brake hose guide. A short length of fuel line split down one side and slipped on the brake line pads it through the guide. The holes in the lower triple tree are already there for you, drilled and tapped .....
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