Almost burnt down this moring...GREAAAAT..

[Guest]

SOoo, I rode to work this morning, after dickin with those carbs my whole weekend, just to see how she'd do...still needs dialed in a bit, down low especially. At any rate, about half way there, i start noticing every time i let off the throttle the bike decels rapidly, at first i was thinking i was having engine trouble, because i had just rebuilt my rear master, and pulled the caliper apart and cleaned it a couple weeks ago, so i didnt think anything of that, and my front was responding fine, but then i notice my rear brake has gone stiff as hell, so i limp it to the nearest gas station and by the time i get there theres so much smoke pouring off the back of my bike i cant tell what the hell is on fire... Then the smoke clears a bit and i see its coming off my caliper. The pistons are stuck, and rubbing like a SOB and cooking the fluid. $HIT! No good at all..im very irritated because i stripped that damn thing apart and found nothing, no rust, dirt, glop, no warping, nothing...Luckily there was a guy there in a work van who lent me an adjustable wrench and after it cooled a bit i loosened the bleeders and pumped some fluid out, careful not to let any air in..i used the wrench to push the pad off the rotor and limped it to work without using the rear. At lunch i had a buddy from work run me home to grab a wrench, my bleeder kit and i bought some new fluid and flushed the system, hoping that the little bit of sediment i found in the bleeder kit resoviour was the culprit. Alas, it was not as it started to get tight again on the way home.. I repeated the process from earlier in the day and limped it home. So now i dunno..ill strip the caliper apart again and see if i see anything going bad..Other than that i cant say what the hell is causing it?

Anyone have any idea?
Whats a good place to find complete rebuild kits for these?
ORR Is anyone looking to sell a caliper off a parts bike they have??

Thanks!!

TCK

[spyug]

Did you do anything to the rear master cyclinder?

If not it is likely the problem. If there is grunge in there it can seize the piston causing the caliper to lock with the pads full on. My bike had sat for 7 years before I got it and exhibited similar symptoms.

The brakes are , obviously, a closed line system. What affects the caliper can also affect the master and vice versa.

It is always good practice to clean and rebuild both ends.
Check it over and let us know what you find.

Good luck.
Spyug

[salty_monk]

www.z1enterprises.com do the rebuild kits for about $17 from memory.

Dan

[TheCafeKid]

I rebuilt the master at the same time...Actually the master was the original project, and i thought, with the amount of crap i found in the master it would be good to go thru the caliper as well. the funny thing is i rode for a couple weeks on and off before this and didnt have a problem..but ill tear it apart again and see what i see..

[97Intruder]

Man, T.C.K....if it wasn't for bad luck, you'd be sh$t outta luck! My brakes were dragging pretty good on the old beast when I got her, had to pull the calipers off, and push the pistons back in(front and back)....lubed the crap out of them, and they have been fine since.

Hope your luck improves, or you hit the lottery, and can buy a " better " GS!

[n1elkyfan]

I had a similear problem on my bike, minas the smoke. I had to clean the frame where the pedal passed through it. It was really gummed up but once I got that cleaned my rear brake worked perfectly.

[TheCafeKid]

Man, T.C.K....if it wasn't for bad luck, you'd be sh$t outta luck! My brakes were dragging pretty good on the old beast when I got her, had to pull the calipers off, and push the pistons back in(front and back)....lubed the crap out of them, and they have been fine since.

Hope your luck improves, or you hit the lottery, and can buy a " better " GS!

Man you aint kiddin...im seriously considering shutting her down for the winter already..saddens me to say so, but the carbs arent right, my starter clutch seems shot and there something seemingly rattleling around down there near the rotor probably a sheared bolt from the starter clutch...who knows...bottom line is she needs help...i wanna ride but not at risk of totally F-ing her up...i dunno man...

[bwringer]

Before buying an aftermarket rebuild kit, see what the OEM parts cost. You'll often get better quality and a more complete kit for less money.

For example, the front rebuild kits for my GS850 are $26 each and only included a few seals of unknown provenance, but the OEM kits ordered from BikeBandit were $14 each and included the pistons.

I also ordered the little boots that go on the slide pins and the little clips that always seem to rust away, also not in the aftermarket kit.

[TheCafeKid]

Hey thanks Brian...i honestly didnt think all that stuff will still be available..most of what ive looked for OEM on this thing is no longer made...38 bucks for what seems to be pistons cups and all the seals..not too bad considering the aftermarket on Z1 just has the seals and its 22 bucks...

[DanTheMan]

Check out your flexible rubber line to the rear caliper also. It may be deteriorating from the inside, you should probably replace it as well.:-D

[Eli69]

i gotta second the check the brake line thing. the flexible lines can get stopped up and there isn't enough pressure to force the fluid back through them into the master cylinder. it happened on one of my bikes and two of my minivans.

[Jd Powell]

Grease your slide pins!!!

The only time I had that problem, it was with my front brakes. Be sure to regrease the caliper slide pins w/caliper grease. also the pins are different so dont mix'em up. Almost every old bike caliper that I have pulled apart has suffered from serious gunk buildup and this will prevent your brakes from releasing. Hope this helps.

[Steve]

Chances are, you don't need any parts. :shock:

When the brakes lock up like that, it is the compensator bypass in the master cylinder that is plugged. Take the master cylinder apart, look in the area where the piston and seal normally rest. You will find a small hole there. Use a strand of copper wire to dig out the crud, then spray some brake cleaner and compressed air to make sure it's open. Had this happen on two of my son's bikes and one of my own. 8-[

If you need help, you've got my number, I'll be back on this side of the country on Thursday.


.

[Big T]

Crud in the brakes will do it every time. A few other suggestions:

1. Convert the brake line to stainless braided. The old ones can delaminate inside, creating a one way valve
2. What did you use to lube up everything when you reassembled? Brake fluid is best, silicone spray is Ok, oil lubes will swell up your seals and lock up your calipers.
3. Be sure to clean and grease the slides as noted above

[TheCafeKid]

Thanks for the imput everyone!! I will be stripping the caliper down tomorrow and looking, as i think the sediment in the lines and posibly what i used to lube it up (PB- guess you *cant* use it for EVERYTHING..lol) may have contributed to it...we'll see..steel break lines for sure will be another thing to purchase very soon if this doesnt do the trick..not sure bout the inside, but the rubber line seems to be fairly new..let ya guys know what i find! Thanks again!!