Jaws Blackbirds. Motorcycle parts supplys for the Blackbird Did your tech "rebuild" your brakes? It shouldn't be that difficult to sort out, imo. Yes, I have my own tech but he seems to know what he's doing. Good Luck

 

The front brakes slide on pins and they need to be clean and greased. Hopefully your mechanic did that. It's an easy check just by pulling the bolt/sliders out. Also what happens at times is there is a relieve hole in the bottom of the MC under a small stainless steel shield. It will get plugged up and not release the brake pressure by not allowing fluid back in to the MC. Easy check, take MC cover off and take out shield. Operate brake and when you release you should see fluid return in to the MC.

Check that out first. I don't think it could be the rear MC causing the problem because they work fine you said. Let us know what you find.

 

Operate brake and when you release you should see fluid return in to the MC. .

Actually, that's a good point. I see fluid come in when I press the brake, not when I release it. I guess that's right in that the piston would first push fluid out through that as the path of least resistance until the piston passes the return port.

Maybe the lack of any visible surge once the piston is returned means there's no significant counter-pressure from the system (ie. seals) sufficient to produce one, and hence the pads stay on the disc?


D

 

As above, the relief port in the master would be my thought.

 

+1Also it's very easy to take apart the master and clean it thoroughly. Also a rebuild kit is a good idea since you are there already and they're not expensive at all

 

That's interesting - I read Tigre's comment on the return port, but I couldn't see one at the bottom of my MC under the fluid. I wasn't aware of another shield - I'll check. That was also my thought, but assumed my late model bird didn't have it. Thanks guys!

 

How dark is your fluid?

 

Pretty light - it would have been changed with the pistons, and again with the recent service. Plus pretty much again just now with the bleeding process My DOT4 is out of date though - 6 months - but that would lead to sponginess, not sticking, right?

 

It's probably what the guys are saying above,as something is interfering in the retraction of your pistons and operation of your MC.
What should concern you is your mechanic should have noticed discoloring in your fluid (maybe their was none) and general condition of your pad wear and operation of your brakes
no use repairing something while some other part in the near future needs attention or needs to be replaced.
You'll sort it out.

 

Just missed your last post damoske
I wouldn't worry about a few months of expiring as long as the bottle was sealed and out of sunlight
but sponginess is one,don't think sticking is.

 

Yep, I was expecting it's just a timeframe in which it's expected to absorb atmospheric moisture, or similar. I thought maybe the fluid degraded over time, and wasn't sure how sensitive it was to that. Thanks!

 

Just ruling out the obvious, the reservoir isn't overfilled is it?
Are you testing with the lid off the reservoir (dangerous with fluid splashing about) or with it screwed down?

 

Can you overfill? There's air on top, if that's what you mean - since I'm parked on a camber with the handlebars over, the fluid isn't level, so I just fill it so it's nearly over the edge - I'm guessing 80% full.

I've tested variously with the lid screwed tight down, screwed loosely down, and one or twice, off entirely (carefully!).

D

 

I just came across this in an article. "Another is not to overtighten the front wheel spindle (just 59NM / 44ftlb is correct) as it can pull the wheel and brakes out of alignment." Have you had your front wheel off lately?? Plus you tighten the spindle first then the four pinch bolts.

 

I haven't taken it off for a long while, but I'll take the torque wrench to it and see where if it pings much higher. Thanks!

 

$700 for pistons !!!! are they friggin gold plated

 

You made me check. $778. Each piston was $35. Welcome to Sydney, where labour is $99 an hour + tax. It could be high time/costs for the area, I'm not sure, but this mechanic was pretty reasonable for the area when I first scouted around.

 

Yes $700 for pistons and labour seems seriously high,but I haven't priced it out yet,the seals are a mandatory change when servicing or replacing pistons.And no 2007 should be that badly corroded-usually,unless you're near the salt air.You did mention it sitting for awhile which will cause moisture to accumulate in the brake fluid,PISTONS to seize up,I'm wondering if the situation has just repeated itself do to a year of being parked.It did every spring on my 600,my garage is very damp come spring time and every first start I would have to give the calipers a smack,not usually a problem after that.
Like RollinOn is saying you really have to go over the whole set up,not just bleeding.Right now I'm questioning this mechanic too.

 

And no 2007 should be that badly corroded-usually,unless you're near the salt air.You did mention it sitting for awhile which will cause moisture to accumulate in the brake fluid,PISTONS to seize up,I'm wondering if the situation has just repeated itself do to a year of being parked

I'm around 800m from the ocean, so the sea isn't splashing on it, nor can we 'smell' the sea, but I guess the wind could carry a little salt moisture; it's not great, although I keep the bike covered and it's not particularly corroded - particularly not in functional areas, it seems.

 

That's a lot of dosh for that work as stated above. New pads, Jaws rebuild kit, Motul 5.1 Hydraulic fluid, there's barely $200 if that. 4-5 hours labour, OMG, I had all lines replaced with Goodridge for less labour than that. I don't necessarily like to dis a tech but I just think you need a 2nd or 3rd opinion. Good Luck.

 

OK - so, after yanking a strand from a wire brush, I set to work today.

I found the return port easily enough - the cover came straight off. There was no visible crap in there at all, but I pushed the wire into the port, and it went in around 3-4mm. I tried this a few times, and also carefully and slowly worked the brake handle to see if maybe the port was blocked by the piston, but it seemed fine. When I pumped the brake (slowly!), a jet came up from the return port, so it seems to be clear.

I had a gut feeling nothing had changed, but it felt freer, so I took it for a 15min ride. Got back, put bike on centrestand, lifted the front, and.... it spun a quarter rotation. Just about the same as before, with no improvement. I felt the rotors, and all were hot... OK to tap, but not to hold, with the front right being hottest. I'm not 100% that the heat was from using the brakes a minute or so beforehand, so I'll need to test that again - just drive with engine braking alone, then stop and see whether they are hot from rubbing.

So I then tried bleeding the top right nipple; the fluid shot up 3cm immediately from the mystery residual pressure, then rose slowly and continuously, I guess just from gravitational pressure (not sure why it would do that otherwise).

So... I'm stymied. I'll have another look at the MC diagram and think through where the other potential issues are, but the return port fit the bill so well, I'm annoyed it didn't turn out to be that.


D

 

Also, the brakes have a dry sound to them when applied, and don't have much bite.. I suspect the pads could be glazed due to the rubbing, and am debating whether to replace them before or after I fix this problem....

 

After you opened the bleed nipple, did the wheel rotate easier? Did you try the nipples for the centre pots? It's possible that the problem comes from the pedal circuit - the proportioning valve comes to mind here, as the rear wheel is not binding.

 

Yep, I tried that before. There's no pressure at the center nipples. The wheel did rotate easier once I bled the upper nipples. So there's pressure in there, it's just... from what?


D

 

Suggestion: Do a static test of the system without riding it. How do you do this? Simple: apply the brakes as if you are riding but do not ride. Simply pumping the brake lever will be fine I should think. Pump as many times as you like to attempt to load (pressure up) the system. With that done now raise the front wheel and spin the wheel to see if the brakes are dragging once again. If yes, try the brake bleeder again to see if pressure is present in the calipers (I'd expect that there will be if there is brake drag). The pressure may be less then you noticed before after your test riding as there is no heat involved in this static (no moving) test. When the brakes heat up the heat will/should help to increase the system pressure due to fluid expansion. I'd aslo suggest that any test riding you do should be very short in duration and close to the home base. No need to get things so hot that you end up warping or glazing the pads and rotors.

This happened to me back in 2012 when I went to change the pads out. The new pads of course had me pushing the caliper pistons back into the caliper bores so that the new thicker pads could be fit. I had hot rotors within a half a block of the house on the test ride. I could not get the caliper piston clean enough (without a complete tear down) to not foul the caliper seals so they ended up jamming up the system. The cure was to put the old pads back on (still had lots of life left,..I just wanted new pads to go with the new wheels and new brake rotors was all). The re-build and piston clean up and new pads are slated for this season coming up. Have you installed new pads by chance?


Tony "I brake for beer" Bagley

 

Hi Tony - no, they're pretty well worn...

I'll do another couple of static tests. Otherwise, looks like I should strip down the calipers and check again!

 

Hi,

Just thought I'd share how I got this fixed.

Well - I didn't. I took it to Close M/cs in Sydney's Inner West, and they spent a total of 6 hours doing various clamp tests, static test, disassembling the calipers, etc. They eventually worked out it was something to do with the right caliper, but stripping/rebuilding wasn't a fix, so they sourced a replacement secondhand part, fitted it, and the problem seems to be better.

It's still not entirely free - a spin will now take it half a turn - but at least it's not leaving a layer of brake dust on the wheel after 10km. They were really good as well - only charged me for 3hrs rather than 6, so it wasn't even into 4 figures including the service. I thought it was going to wipe out a year's savings.

D

 

Sounds to me like you need to spend some quality garage time with someone who can show you the ropes. That garage is spooning your eyes out.

here is a guide that i did some time ago. OK its on an RC51 (aka SP1) but the principle is largely the same
How To - Service your brake calipers | Teesside Bikers

 

Thanks, I'll take a lookI don't think they were having a go - I had already spent $700 at another shop (Blackbird specialist), who had stripped and services the calipers, and couldn't fix it. This shop spent 6 hours claimed, and likely true judging by the number of phone calls I got over the 3 weeks, but only charged 3.

 

Well its good that the brakes are better but not perfect now ..... I was beginning to think it would be cheaper for me to fly down and fix them!

Something that I haven't seen in this thread is was it a piston issue (probable) another issue or a combination of issues.

With brake binds (and assuming the pistons are clean) it is 'simple' to see/measure which piston is not retracting thereby isolating which part of the system is playing up - essential with the LBS system if you are not to go round in circles.

Did anybody who looked at the bike find this out damoske?

 

i've been having a similar issue on my '97. i bought it used, having sat around for who knows how long. when i opened the m/c, i was rewarded with a reservoir full of brown pudding. nasty!

i stripped, cleaned, and rebuilt EVERYTHING - all 3 brake m/c's, all 3 calipers, and cleaned but did not replace the lines.

i could ride between 1 block and several miles before the front brakes rapidly tightened and then completely locked up.

i read all the brake-related posts i could find and tried everything EXCEPT checking the fluid return port. i "knew" it was clean, since i had just overhauled and cleaned the entire system.

finally having exhausted everything else and just before starting all over, i popped the little splash guard out of the return port and wouldn't you know it, the port was 100% clogged with hard brown gunk. evidently there was enough gack left in the lines to back up and clog the port even though the new fluid and every other part in the system was clean and crystal-clear.

an old guitar string and syringe cleaned the hole and sucked the gunk out, and now my brakes work great.

just a heads-up for now or for posterity to check that return pinhole, even if you have just overhauled the whole system. the fact that a new (used) caliper exhibits the same issues for you makes me wonder if a clogged return port or clogged/crusty old line are the culprit.

cheers!
ron