Brakes, what did I do wrong...

[newc4]

I did the brakes on my SF last weekend and had a similar problem. The cylinders would move slightly then return. Finally I adjusted the screw on the brake handle itself and now they grip tight.

Darrell

[petejw]

have you bedded in the new brake pads?
if you havent then they wont lock up,
id also make sure youve got air out of the lines
by bleeding the master cylinder whilst it still on the bike,
just crack the banjo bolt and pull in the lever and see
if any air comes out, be careful not to spray brake fluid
every where.

[psycoreefer]

I've been bleeding for hours......

ok, my last post was at 9, then I went out to the garage and tried to bleed the brakes more.... now its 12, so I've been bleeding for 3 hours, plus the time I spent earlier today.

I hung them from the ceiling, I did a dance, I prayed to the XS gods, I even sang them a nice song about air and all the reasons it doesn't belong in my brake system. Nothing Came Out except brake fluid.

Pete, no I haven't "bedded" them in, but I shouldn't be able to pull the lever all the way to the handle bars.....

So, I tied the calipers up high, pull lever, crack bleeder -> no air, repeat until I had about 4 oz of brake fluid in my handy brake bleeder cup.
Repeat for the other caliper.
Tap on the master cylinder and line leading to it, pump lever, no air comes out.
Pull lever, crack banjo at master, fluid leaks out.
Brakes are still soft -> lever goes all the way to the bars
Pumped brakes with caliper off until caliper piston was almost all the way out, then pushed piston back in, forcing fluid the "other" way. No air, just fluid comes back out in the master cylinder.
Took the master off the handle bars and rotated and tipped it in all directions in case there was a bubble stuck in it, nothing...

I really really don't think there is any air in the lines.

Thought about swapping the master from the other xs, tried it and I can pull it all the way to the bars too. What are the chances I've got to bad masters? Maybe I'm just too darn strong?

[rpgoerlich]

Maybe the front cup in the master cylinder got flipped around during assembly?

Try holding your finger over the master cylinder with the line off and pump to see if you can build up pressure. If so, connect the line and do the same at the end of that line. If not I'd say the master is letting pressure back by.

[greatnw]

I'm thinking the same thing about a cup on the MC stem being backwards. I have a special and rebuilt the mc's and calipers. bleeding was not a problem. Sounds like there couldn't be a molecule of air in your system so it almost has to be master cyclinder. I know I had to noodle out the correct order and orientation for the plunger. Good luck!

[fredintoon]

Hi psyco,
I fitted s/st lines to my XS11SG and those bastards would NOT bleed out. After two days of cussing I ended up teflon tape wrapping the bleeder nipples, rigging an IV set up on a tall step ladder and backflushing to get the system air free.
Meanwhile my son fitted s/st lines to his XS750 Special (exact same brakes) and had them bled out in a half-hour.
TANJ! ("there ain't no justice" a printable obscenity from author Larry Niven)

[Yard Dogg]

Sorry pscoreefer. I had a 12 round fight with mine too. If you look at your calipers, fittings and master cylinder and see no brake fluid leaking. Then it can't be spongy for any other reason than air. It only takes one little bubble. Keep plugging away, you'll get it.

[Larrym]

Odd Man Out Again

psycoreefer,

Huh? I keep hearing reports of owners having difficulties with bleeding the front brake systems of the XS. Usually accompanied by the tales of the heroics involved or the caliper/MC gymnastics/repositioning/reorientations which "finally got rid of the air bubbles." Ok. I'll go along with the notion that each owner correctly connected the dots between what they did and what eventually worked for them. Even if it goes something like, " I had to hold my mouth just right."

In my experiences with my old standard and my current special I seem to have missed out on all that. The standard: just flushed out the whole system with fresh fluid without any disassembly. The special: had to pull the caliper pistons out on both sides, do the detailed cleaning inside, and reassemble. Also did a total fluid drain first (calipers and MC) so all that was in there was the air that we breathe. So on the special I really did have the conditions where I should have reported in the forum here that things weren't going smoothly.

But I didn't have any unnecessary drama. And by now hopefully, the members here would know that if I did, I would have chimed in with not just one posting but a series of posts which would covered every action/observation/reaction in absolutely nauseating detail. Pictures, 3D photos, video and my blow-by-blow narrative.

No special "vacuum brake bleeding system".

This is similar to what I had and used:



No "speed bleeders" either. I second the recommendation of using the teflon tape wrap around the threads of the the OEM bleeders. I always do that cause every time I've tried to do a one-man-bleed on any brake system without that tape, air has slipped past/through the threads when I did the return stroke on the MC. (Cars, bikes, quads, etc.)

One more thing which I seem to "depart from the norm" here is that I don't ever use the full MC plunger travel in the bleeding process. (Or the brake pedal travel in automotive). That is I never "bottom out" the lever. In fact I take a piece of wood and tape it on the throttle grip between it and the brake lever. Can't make use of the full stroke even if I wanted to.

Like I said, It's worked for me. Also reproducible results on two XSes along with numerous other makes, models, and years of bikes. (Gonna rule out the cars/trucks for now at least.).

1. Teflon tape on the bleeders.
2. One-man-bleeder kit.
3. Block of wood between lever and EOT. (End Of Travel.)

Could never hold my mouth just right anyways...

[xs11lover]

I just went through the same thing last week on my 79 special. I took everything apart, cleaned, even painted em. Don't forget to clear the spooge hole in the master. I put it all back together, but left the master a little higher on the bars so it would hit the righthand switches before it bottomed out..and pumped, and pumped, and pumped, forever..tapped all the unions with a rubber hammer.....got the fluid down and the air out, but no brakes, or at least hardley any. Spent most of the day on it, then pulled the hadle back and tied it off over night. Started working it again the next day, stil nothing, I thought I must have put the master back together wrong or unseated the seal with all the pumping, so I ripped the master apart. It was all just as it should be.
I put it all back together and started pumping again with the master cover off...very slowly pumped and this time I could watch air come up from the spooge hole on the return stroke. It still took forever to pump up some...tapped all the unions with a rubber hammer...over and over...then my 14 year old kid came home from school and I told him to work them. He's got the touch...really slow and short strokes...and the little know it all puke pumped them up hard as a rock! I can rent him out for the day.