So, that 2002 R6* radial master cylinder I mentioned.
(http://i.imgur.com/pq1XRWZ.jpg)
It's pretty plug and play, which is cool, in that it just 'fits'. (I'll get a picture of it mounted tomorrow). After extensive research, I have determined that it is a 14mm inner diameter, which is perfect, from what I remember! (ctr+F "master cylinder" here (http://rs.e-racing.cz/storage/manual/yr6csm_1999_01.pdf)). At least, that's what I wrote in the wiki (http://fjowners.wikidot.com/brakes#toc2) at some point in the past, but I didn't provide a reference, so I can't say with absolute confidence. I note that the one Randy sells is 19mm, so I'm really not sure.
Anyways:
I haven't gotten it working, which means for the time being, I'm driving without front brakes. :bomb:
I didn't get much time to figure out why. Huge storm hit just after I had put it all together, and my workspace is on the opposite side of town from home... Here's what I'm thinking:
The original banjo bolt that screwed into it was meant to have TWO brake lines connected (which went straight to both calipers). The stock FJ M/C banjo bolt only has room to fit one--then it goes down to a splitter mounted on the yoke, where two short lines feed to the calipers.
The stock brake line (yes, I know, they all need to be replaced) is too short to quite reach the new bolt-in spot on the new caliper--just no way around it. So I took a longer line that was from the R1 and put it in. There's some extra, but it doesn't get in the way of anything the way I have it fed. I also used the banjo bolt from the FJ M/C, so I could attach one line in.
There's a chance I just need to mess around with it more and it would all work out, but I wasn't really getting the response I expected from my pressure bleeder (one of those 'guns' with a line, a reservoir, and then another clear line that you put on the bleeder screw, and as you squeeze it, it sucks fluid through the system) on the calipers. I know how to use the pressure bleeder with confidence, because I just used it to get my rear brakes setup, and they're perfect now. But fluid just wouldn't come... It would just keep building pressure. Fluid level in the reservoir stayed level...
Of note, there is a bleeder valve on the M/C itself. ???
What am I supposed to do with that? I tried sucking on that, and got a tiny bit of fluid out of it.
Am I forced to use the original banjo bolt, with a spacer (or longer lines that go straight to the calipers? I wouldn't imagine no, but now I'm not sure.
Ideas, anyone? I've never modified a brake system, only dealt with stock setups.
Oh, one other thing. I see the plug-ins for the brake light terminals on this thing. Which is positive and which is negative? I couldn't really squeeze the lever and be behind the bike to see the brake lights at the same time, so I couldn't figure out how to tell. I guess I need to get a friend.
But then I realize: it looks like my brake lights aren't working. Did I blow a fuse trying various configurations somehow? Anyone have any insight on why my brake lights would suddenly not be working? I know they had been working fairly recently, but I can't say for sure they were up until the moment before I checked... But my guess would be it is related. Ideas?
There's a lot of words in that last post, and I'm pretty calm about it, but this one is kind of *URGENT*, because this is my only vehicle, and I'm without front brakes until it is fixed.
On the other hand, I am taking a week off on a road trip with the girlfriend. (She didn't feel like doing the few hundred miles on the bike).
That's good because I won't be driving around without front brakes!
On the other hand... During that time I will be leaving the bike with the welder so he can make measurements to modify the GIVI rack so it mounts on the same spot as either the rear passenger footpegs or the exhaust bracket (haven't decided yet). I would really like to be able to have my brake working before I give the bike to him so an accident doesn't happen while he's pushing it around and suddenly he reaches for the brakes and it won't stop!
I figure it's something simple. Just a matter of having the knowledge.
Just recently had a similar problem with my rear master cyl.. No or minimal pressure, tried reverse feeding, no luck. Disassembled the cylinder and noticed the small orifice (you have two) was plugged up. That orifice is about as big as a pilot jet.
Cleaned and put back together, works great now. IF they have been running DOT 5 (&*^%$^) and mixed or converted back to Dot 3 or 4 I am told that kind of crap will show up. The plugged material I had was crusty varnish like thats the best I can describe it.
Pull it apart and clean it good. I reused the old seals.
Don't know if that will help but that was my experience. Also as a note my stock FJ front master cylinder with blue dots seem to work good...
George.
I have blue dots, but I only have a 16" wheel, and so nothing to mount them on. :cray:
The caliper has been sitting dry for a few months in storage. I guess cleaning it could be in order. I just don't know how... It's radial! haha. I've always checked for bubbles at the bottom of the reservoir, but on this one, the reservoir is remote! What to do...
Quote from: fintip on April 08, 2014, 12:00:16 AM
The calipers and master cylinder have been sitting dry for a few months in storage. I guess cleaning it could be in order.
FTFM
Have continued research, have read that polarity does not matter on hooking up brake light wires (assume this applies universally, and that's why it's not indicated on unit itself), and saw a video where each caliper was bled, and then the M/C itself was bled. So it's not for magical reverse bleeding or something, good to know.
Just the question of the single/dual banjo bolt swap being ok, I guess. If I can be sure that doesn't cause problems, I guess I can safely assume something is blocked in the M/C itself.
Confirmed (now it's night) that I have no brake lights, front or rear. (!) That's new. One of my bulbs looked like it had the 'running' circuit blown a while ago... May just be time for new bulbs and a fuse. Don't know what the cause was, nothing I did should have changed that. Weird.
Well, really not so sure anymore. Kind of a hard topic to research, but I found this thread (http://www.gixxer.com/forums/showthread.php?t=261157) where someone makes this comment:
Quoteare you installing the lines 2 off the master cyl? or one line off the master cyl then one from one caliper to the other? If you are only having one line off the master cyl then that is the issue as it's a two line off the master set up
Of course, I'm not quite doing either; we have option 3, single line on the master to a splitter. Hmm. Maybe this won't work without brake lines ordered to set it up as a dual-line setup?
Here's a relevant question:
If my M/C was dirty and that was causing the problem, wouldn't I have a stiff handle, instead of a pressureless handle?Edit: continuing research, I find that brembo sells master cylinders, and offers to include single or double banjo bolts (http://www.bikehps.com/acatalog/Brembo_Radial_Front_Brake_&_Clutch_Master_Cylinder.html) according to your preference, if I'm reading this right...
Edit2: talked to that mechanic I apprenticed with, he assured me that swapping from a double to a single banjo should be fine.
So, all the answers for posterity:
Single line banjo bolt is absolutely ok.
I just needed to trust the thing and keep bleeding, it eventually worked out.
The brake lights worked; the problem was just the rear pedal's ability to pull the switch. Since finally fixing my rear brakes, the amount of travel on the rear brake pedal is drastically decreased during normal use, and it was no longer triggering the switch. It had to be unhooked and disconnected, removed, screwed out, and reinstalled. It now works fine. The R6 brake lever activates it just fine as well, I just didn't have it hooked up last night and had assumed if the rear brake lever wasn't activating it, something else must be wrong.
The M/C exhibits a lot of fading and almost certainly needs to be rebuilt (either shrunken/dried or torn seals inside), but if you pumping it a few times, you then get the full effect: wow. Amazing. It changes everything. I feel like my front dives more, my brake feel is drastically increased. I didn't know what to expect, because I was pretty satisfied with my brakes as-is before. Amazing how big the difference is. And again, truly a plug-and-play install. 7/8 bar mount, no pieces to remove with a sawzall, just... works.
Now to rebuild it so I don't have to pump before every use.
Sidenotes, found a forum member who seemed to know a lot about brakes on another forum who mentioned that the hydraulic pressure doesn't change between different setups (a line to each caliper straight from M/C, or a line to a T fitting, or one line to one caliper, and another connecting the calipers), so there's no performance bonus for using the double banjo bolt. The stock lines from the R6 are too short to use on the FJ. The line I borrowed actually does bind as fitted if the bars are locked all the way to the right against the tank. I got another line today from my mechanic friend's spare pile for the time being, will put it on when I rebuild the M/C.
Verdict: if you don't mind the 'urine cup', or put performance before aesthetics, highly recommended. Cheap/easy 14mm radial M/C conversion.
Fintip,
I would assume the MC is ok unless it leaks fluid. You probably still have some air in the system, as it seems to pump up. I would try bleeding it again after sitting it overnight; does not seems safe to ride to me if you have to pump up.
Jeff
A few random thoughts about the information here.
I thought I recall Jon Cain (or was it Pat?) saying to use a 19mm master if it was a radial. I can only assume that what you're using does actually work since it was used for blue dot calipers on the R6 it came from. If you're having to pump the lever then either it's still not bled well, or the master cylinder piston is too small and you're having to grab an extra handful of lever to pump enough fluid to generate pressure.
In theory, the number of lines should not matter. As long as they do not expand under pressure, they will transfer the pressure down to the caliper piston. Thinking about it, even if they do expand (assuming you're squeezing with a constant force on the lever) a little more lever travel will compensate for the expansion and keep the pressure at the desired amount.
Well, I used a pressure suction system on all three bleeder nipples. I was getting fluid everywhere as soon as I squeezed. And I visited my mechanic friend to check it out, who runs his own shop and has been working on old jap bikes for 30 years. His assistant and him both said that the fade they felt was the symptom of needing a rebuild. Sitting dry for months is a perfect explanation for that. However, that's new to me; my only experience with a bad master is it just doesn't hold pressure at all. But they both have waaaay more experience and knowledge with hundreds/thousands more bikes than I've ever dealt with.
As I pointed out previously, Randy sells a 19mm master, so that's definitely possible. I'm curious why radial should make a difference on piston size, though? The only difference should be leverage directionality/linkage changes, not any volumetric change, no? Would love for Pat/John Cain/anyone else with knowledge to weigh in on this, definitely not my expertise.
The symptom is it is completely soft for the first two or so pumps, and then perfectly hard for the third or fourth pump, essentially. But very quickly fading back to completely soft again.
I drove without rear brakes for a year. It sucked, and it cost me two small lowsides in unfortunate circumstances. Driving with great rear brakes and "special needs" front brakes is actually still a general upgrade from what I had been experiencing. Certainly not ideal, but... When it's your only bike.
I'll leave it ziptied overnight and see if that helps at all. Tomorrow morning heading out of town, though. Figure I'll order a rebuild kit before I go.
Edit: found this (http://www.fjowners.com/index.php?topic=3656.5) thread where Pat and John Cain are talking radial and other M/C's.
I don't feel like it's definitive or very well understood/explained there, but JCain says he was using a 14mm radial, and then upgraded to a 19mm radial.
Quote from: JCainFJ
I have been using the 19mm radial master (made by Nissin) from a 2004 GSXR 600 on my YZF600. It provides improved feel and controle vs the 14mm R1/R6 master I had been using. One of the best features that the radial Nissin master has is the bleeder located at the top of the bore. It makes for very quick purging of any air. The 5 position adjustable levers are nice too.
I have also purchased a set of Nissin radial masters from a Kawasaki ZX14. The brake master is a common Nissin 19mm radial, so lots of Kawasaki, and Suzuki levers will fit. The clutch master ( again a Nissin part) is a near mirror image part to the Brake master. It is marked as being a 3/4in bore. The bigger bore of these radial masters works out to be the equivalent of the non radial masters I had been using.
I have also made up a few remote reservoir mounts for the clutch side, simple clean parts like always.
Quote from: Pat ColonLet's talk about that for a minute.....Help me out. Bore equivalences between radial vs.non radial m/c's. How does that work?
I know thru experience that with conventional non radial m/c's when we replace our~16mm (5/8") m/c with a smaller 14mm m/c we get a lighter 2 finger action on the lever, yet with a longer stroke.
So how is it that we use a larger bore with radials and get even a lighter lever feel? Is it all due to mechanical efficiency of the radial, i.e. having the piston travel in parallel to the stroke of the lever. That much? I mean a 19mm radial m/c having a better feel and lighter touch than a 14mm?
14mm piston area=154 vs. 19mm piston area=283 so a master cylinder with a piston area 80% larger, yet with a lighter feel, all due to mechanics?
14mm vs 5/8": I was just getting my head around how a smaller piston with a longer stroke can give a lighter feel or pull at the lever, now you turn my world around and tell me a larger piston will be fine.....
Quote from: JCainFJI think that the geometry is quite a bit different radial to non-radial. The distance from the bore to the lever pivot is shorter on the radial master, so a given movement at the lever moves the piston a shorter distance. That's why the piston has to be bigger.
I have also noticed that the radial masters deflect less then the in-line masters do. That may be why the radial masters provide better feel. Braded lines eliminate the flex (think of it as a spring) of rubber lines and that provides better feel. The monoblock calipers flex less then the earlier bolt together 4 piston calipers and provide better feel too.
I actually mounted a dial indicator (CA is great stuff) to one of the stock calipers on my FJ and then to an early monoblock and found that the monoblocks flex about half as much as the stock FJ calipers. (We have some long winters here in Cincinnati) Some of the older calipers you can actually see flex when you apply pressure.
One of my pet long-term projects is designing better clutch and brake hand controles. The OEM,s have done some work on these systems, but I think there is still a lot to be done.
If I'm not mistaken, he is using the 19mm on his YZF-R6, though?
I also found another thread where Arnie remarks to someone wondering whether they should get a 19 or 14 mm radial:
Quote from: ArnieI don't know how to compare the size of "radial" master cylinder bores to "normal" master cylinder bores.
For "normal" m/c the smaller the bore, the easier it is to squeeze the lever.
However, the larger bore units displace more fluid for a given distance moved.
This means that for a given set of calipers.....
A m/c with a small bore will take less hand pressure for a given
amount of disk braking force (squeeze). It will also require more movement of the lever.
You should be able to moderate this easier (and maybe more accurately) than a large bore m/c.
If you have strong hands, you'll be able to get the same braking force with
less movement of the lever on a larger bore m/c, but you'll have to squeeze harder
and may not be able to moderate the braking force as accurately.
Potential problems with each:
Large bore m/c: You may not be strong enough to get maximum braking or to control it
Small bore m/c: You may run out of lever stroke and hit the bar before max braking.
Neither is "better", it is another choice you have to make.
Arnie
So I'm really not sure. I haven't really been able to find a thread yet where someone upgrades the M/C but leaves the stock calipers on.
Okay, information overload. Stop repeating old discussions and concentrate on one problem at a time. I've noticed that you tend to wander all over the map when you get started on something.
A master cylinder needs to be rebuilt when it starts to leak. If it will pump up an hold pressure without leaking then it is doing its job. I don't understand what you mean when you say it starts to fade. Does it lose pressure? Is it leaking? If so, the it needs to be rebuilt.
Next issue. The size of the radial piston may be different because of where the lever is pivoting and the lever arm and force it provides on the piston. This will affect the feel and efficiency of the brakes. It may very well be that a 14mm radial master is too small and will require more than one stroke to transfer enough fluid for proper braking pressure.
I went for a ride to some places tonight, and observed very carefully. It seems that is likely the case.
First full stroke, it can make my nose start diving, but not lock up. A little before halfway through the second stroke, it allows full braking.
Bummer. I couldn't find one case of someone else having this happen. I do have the blue spots... I guess I can start to hunt for a late model front end so I can put my blue spots that came with it on.
Anyone understand how to do this math? Is there more piston surface area to move in the old stock calipers than the blue spots?
Fin...I cannot, for the life of me, understand why anyone would ride around on a bike with brake issues. Your forum/shop mates have given you their opinions, stop messing about!!!
Buy a master cylinder rebuild kit, strip, clean, rebuild, bleed off...VOILA!!!.
Health and safety for you and other road users restored.
John.
Quote from: Tiger on April 09, 2014, 04:31:50 AM
Buy a master cylinder rebuild kit, strip, clean, rebuild, bleed off...VOILA!!!.
John.
Excellent advice indeed.
Worry about mix 'n' matching components for a bit of fun later but if you need brakes, the fastest and cheapest option, with a known outcome, is as John suggests.
Noel
I'm not leaving it on indefinitely, I'll be reinstalling the old master at the next possible convenience, which will be the next time I ride the bike, on Monday; I get back from the a road trip I'm taking this morning on Sunday. Again, I don't live at a place I can work on my bike, have to drive across town to be able to. No other option... No truck... Just life.
It's not like it's a machine that can't stop, either; aside from being able to manage sane driving with a rear brake alone better than you might think, the front brakes take 1.5 squeezes to function, which is still plenty functional.
Quote from: fintip on April 09, 2014, 08:36:51 AM
...the front brakes take 1.5 squeezes to function, which is still plenty functional.
Really, with 600Lb of bike/rider!!...Until, God forbid, the time that you really need it!!! You know,
that time...that unexpected time.
Sorry Fin, but you are an accident waiting to happen... :flag_of_truce:
John.
Granted. But I won't even be putting in an hour of driving like that, before I swap out the master cyl, and I'll just add in extra caution until then.
You guys should have felt the brakes on my first vanagon. Now that was scary...
Quote from: fintip on April 10, 2014, 09:04:55 AM
Granted. But I won't even be putting in an hour of driving like that, before I swap out the master cyl, and I'll just add in extra caution until then.
Well hey, you didn't tell us that before... that makes it okay then. :wacko1:
Carry on.
Quote from: fintip on April 10, 2014, 09:04:55 AM
Granted. But I won't even be putting in an hour of driving like that, before I swap out the master cyl, and I'll just add in extra caution until then.
You guys should have felt the brakes on my first vanagon. Now that was scary...
It's only a matter of time before your luck will run out. Why poke the bear? :bomb:
UPDATE TO ANYONE READING THIS THREAD IN THE FUTURE:
This is NOT an '02 R6 Master Cylinder. It is also not a 14mm radial. It appears to be a 17.5mm radial M/C off of an '07 (or equivalent year) Honda 600RR. For discussion and pictures and links, see here (http://www.fjowners.com/index.php?topic=11449.msg113588#msg113588).
Not sure in the end if it just doesn't push enough fluid, or really does need a rebuild kit...