Thought I had my brakes sorted. Pulling up to a stop this morning and they wouldn't release. After I was completely stopped and hands off they released. Thought it could be a bulky glove fumble issue, so tried it again on the airport driveway. Same. I had a lot of trouble rebuilding the FZ1 master and I'm thinking that is probably the issue. New brake lever and the pivots are clean and lightly greased. Plan to order new brake lines. I don't think that is the issue but want to cover the bases. May try sacrificing a chicken at midnight or something too. Would like to hear any thoughts the gang may want to share.
Overfilled container can get the brakes sticking after riding (when hot) and releasing again after cooldown because the fluid has no space to expand. I made the mistake once.
Also make sure your brake lines are routed so as to not cause a pinch. A crimp in the line will allow high pressure forward flow but reduce low pressure back flow to the reservoir.
Quote from: Waiex191 on October 18, 2023, 09:05:16 AM
Thought I had my brakes sorted. Pulling up to a stop this morning and they wouldn't release. After I was completely stopped and hands off they released. Thought it could be a bulky glove fumble issue, so tried it again on the airport driveway. Same. I had a lot of trouble rebuilding the FZ1 master and I'm thinking that is probably the issue. New brake lever and the pivots are clean and lightly greased. Plan to order new brake lines. I don't think that is the issue but want to cover the bases. May try sacrificing a chicken at midnight or something too. Would like to hear any thoughts the gang may want to share.
New brake lever - Yamaha or aftermarket?
Thanks guys for the replies. I didn't overfill when I bled the brakes. Should be space and this was just after startup, 34F outside, night in the garage probably around 50F.
I have not changed the line routing, but I'll check. Could be related to fork dive.
Aftermarket brake lever.
I guess you have checked that the returnhole in the resevoir is open. also the atmosphere pressure hole in the lid of reservoir.If overfilled the brakefluid will come out there. im not sure but if that atmosphere hole is not open it may pressurize the brakes.
Quote from: Old Rider on October 19, 2023, 02:07:34 PM
I guess you have checked that the returnhole in the resevoir is open. also the atmosphere pressure hole in the lid of reservoir.If overfilled the brakefluid will come out there. im not sure but if that atmosphere hole is not open it may pressurize the brakes.
I definitely made sure the return hole in the reservoir is open when I rebuilt it before. Everything was clean and had liters of brake fluid flushed through it. I did not think there was a hole from the reservoir to the atmosphere though.
I mean the tiny passage in the lid that make the rubber diaphragm move down when brakefluid level is sinking. Im not sure if it can make the brake
binding if it is clogged bith worth a look if it clogged. As im sure you know there are 2 holes down in the reservoir one is very tiny check that both holes are open use a tin brass wire to poke it open if clogged
Quote from: Waiex191 on October 18, 2023, 09:05:16 AM
Thought I had my brakes sorted. Pulling up to a stop this morning and they wouldn't release. After I was completely stopped and hands off they released. Thought it could be a bulky glove fumble issue, so tried it again on the airport driveway. Same. I had a lot of trouble rebuilding the FZ1 master and I'm thinking that is probably the issue. New brake lever and the pivots are clean and lightly greased. Plan to order new brake lines. I don't think that is the issue but want to cover the bases. May try sacrificing a chicken at midnight or something too. Would like to hear any thoughts the gang may want to share.
I'd try to locate the problem before throwing money at rebuild kits
Wrap some cloth around the top banjo and back the bolt out a few turns to release the pressure, then remove the bolts holding the caliper to the fork leg. If the calipers are free rebuild the master cylinder, if not pull the calipers and check the pistons are free.
I had an aftermarket lever do the same to me many years ago. It didn't allow the master cylinder to fully retract and would build up pressure and lock the brakes up. If I remember correctly I had to file a bit off the lever to allow the master cylinder to fully retract and release pressure.
Thanks for the continued replies. Joe, the brakes release when the stop is done, and the forks decompress. So I can't crack the banjo to release pressure. I'll check the lever too.
Have you fixed it? if not i have more test you can do .Jack the front up so the wheel spins in the air. Does it spinn freely ? if not try to losen the caliperbolts
and spin again then while the wheel is spinning use the frontbrake lever and stop the wheel several times.Then while wheel is spinning tighten the caliperbolts
losely one by one and check if it is binding. I have once had a sticky frontbrake (and wheel) that turned out to be misangled forks and one fork was sitting about 2mm higher in the triple tree.If that is the case losen all bolts wheel bolts and axle clampbolts to exept the upper forkclamps and bounse the front down some times to get the forks to angliment.
Not yet. I removed the clips that hold the brake lines to the fender mount bolt, to see if that was causing an issue. Definitely related to fork compression. A gentle stop is no issue. A hard stop will make them stick until it stops and the forks rebound.
New stainless braided lines are on the way from RPM. I was due for new lines anyway - ask Pat!
Hmmm... Is the anti-dive still connected? I don't see how it could be related but the fact that they unstick on fork rebound makes me wondering.
Quote from: balky1 on October 30, 2023, 09:40:15 AM
Hmmm... Is the anti-dive still connected? I don't see how it could be related but the fact that they unstick on fork rebound makes me wondering.
There is no anit-dive on my '89.
Jacked up the front wheel. Verified that the brake frees as soon as the lever is released. Got my son to help me.
Next we compressed the forks, I think to the stop, and locked them in place with a cam strap. No signs of locking up.
So far that puts me at a loss. The aftermarket brake lever is nice and free.
My brake lines from RPM came today. Can anybody tell me what these things are for?
If I remember correctly - they are used to clock the fittings. The "stic goes through the banjo to lever it around while you hold the fitting in a vice using the "clamp".
Quote from: fj1289 on October 30, 2023, 09:31:36 PM
If I remember correctly - they are used to clock the fittings. The "stic goes through the banjo to lever it around while you hold the fitting in a vice using the "clamp".
So, they do swivel. I had tried by hand and failed, and thought I misunderstood.
Thanks, I ended up clocking one fitting a few degrees. Also regarding your comment on aftermarket levers, I did find my lever was pushing in the master a little bit hands off. I filed down the stop that the green arrow is pointing toward.
That appears to be the stock lever for the 03-05 (06ish) FJR masters that are used with the blue spots. It should not have needed any material removed.
Quote from: RPM - Robert on November 01, 2023, 10:19:39 AM
That appears to be the stock lever for the 03-05 (06ish) FJR masters that are used with the blue spots. It should not have needed any material removed.
Here is the item on ebay I bought:
https://www.ebay.com/itm/323930918730 (https://www.ebay.com/itm/323930918730)
They identify it as aftermarket. It did look a little different finish than the broken OEM one I took off. Also the bushing looks to be aluminum rather than bronze. So I think it is a close copy.
Hope that clears up the problem for you! In my case it just slowly built up more and more pressure and locked up about half way to work. Don't remember how I figured what the problem was - think I finally realized that was the last thing I had messed with!
Yup pretty close copy. I didn't look close enough in the original picture to see the bushing was not brass.
Old brake lines look fine on the outside but can shed little bits of rubber inside.
This stuff can clog the Masters relief port.
Good on ya for getting new Spiegler lines....
Quote from: RPM - Robert on November 01, 2023, 07:17:24 PM
Yup pretty close copy. I didn't look close enough in the original picture to see the bushing was not brass.
It was well-greased in that picture so would have been hard to pick out.
Ok, I'm back. I can't believe the poor bike has been sitting for over a year. I've done a lot on the airplane - some planned and some unplanned. But I felt like I should get the airplane "finished" before I tackled the FJ. Had no idea it would be this long.
First thing is I had to figure out where I was on the brake project. Looked like I was down to routing my new brake lines from RPM. I went with the dual lines and used a couple of loose adel clamps at the horn mounting bolts to control the routing. Finished that, put the horn back on, and bled the brakes. I did a reverse fill through the bleeder, then some conventional bleeding but was not getting pressure. I tie-wrapped the lever to the bar overnight and that did the trick. No more brakes sticking on. My suspicion is that the aftermarket brake lever that didn't let the MC retract all the way was the culprit. Thanks again fj1289.
First ride in almost a year - still rides like an FJ.
I don't know if you had the pistons out or put new pads in if you did though it could be something like what I did. Which was not clean the pistons properly on my old ST1100 when I shoved them in to make room for the thicker new pads. This caused a jam up as the pistons would not return properly.
Now I spray solvent on the exposed part of pistons and get a long enough thin cloth stick the end through and pull back and forth until they are shiny before shoving them in.Havnt investigated a simpler way.
I rebuilt the calipers, master cylinder, and pretty much everything. New pads from RPM, new EBC rotors bought from somebody on the forum here. I generally use isopropyl alcohol to clean brake parts. Definitely not my first time doing brakes. I'm pretty sure it was the aftermarket brake lever that I had to file down.
And now - the FJ is leaking fuel again. Crap.
Bryan, do they use ethanol free fuel for aircraft? Run a tank of Seafoam thru it....
Quote from: Pat Conlon on October 02, 2024, 07:20:09 PMBryan, do they use ethanol free fuel for aircraft? Run a tank of Seafoam thru it....
Pat,
We run 100LL in our aircraft which is great stuff but it has a lot of lead. I have actually been running nothing but ethanol free gas for a couple of years as I got sick of tearing apart my carbs. But this is not the problem - keep an eye out for a new thread.
Glad the brake issue is sorted!
I'm getting ready to do caliper rebuilds, new discs, lines etc. (and new levers .... Hope they don't act up!)
Good to get things sorted one-by-one. Gets a bit demotivating when issues start "stacking up" - always motivational to be able to cross things off the list!