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I have been through what you are going through.I had to bite the bullet and admit the MC was faulty.It's still in a box of spares here,dunno why because I know it's shagged.Some people have bought new ones that were faulty and had to return them even on this or the old forum.



If the MC is right it should be virtually instant using either of my methods unless you have an air-leak in the system somewhere but that should not stop the MC building pressure and allowing a full bleed.The pressure would drop over a short measure of time if there was an air-leak somewhere else once you got pressure.



I could have gone with a rebuild kit but once I stripped the aforementioned MC it was scored inside so no good and also I thought to myself why bother servicing a 30 year old MC when I can get a brand new one for not much more cost?





USA Motorcycles have several that will work,



http://motors.shop.ebay.com/Motorcy...ssn=usa-motorcycles-inc&_trksid=p3911.c0.m282



Over here StartRight do a nice one but I don't know if they ship to the USA,



http://www.startright.co.uk/index.php?main_page=product_info&products_id=7889
 

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Discussion Starter · #22 ·
I think that it's just improper bleeding, as it's doing the exact same thing that my last MC did in terms of pumping the handle to get it to firm up a bit, and then waiting a while without using it'll lose pressure (When riding, not when sitting, and it still doesn't have near as much pressure or power as the last one..yet). Unless both MCs were bad and had the exact same problem. I should've just bought a Chinese MC when I rebuilt my current one, it would have saved me tons of cash. The only reason I didn't was because my friends and family kept telling me that I'd never be able to find parts for a Chinese one if it were to break. Sigh.



I still really haven't done your method yet though, Shep. That's saved for today. I've only done Mityvac and traditional methods so far. If your method doesn't work, and reverse bleeding doesn't work (I wish I would have learned of reverse bleeding sooner, it's so cheap and seems almost fool proof) then I'll put the old MC on and see what happens.



I just wish I could return the thing, but I've cut into it so many times he'd probably send it back to me and laugh.



Edit: after having the lever tied to the handle overnight it feels a hell of a lot better! Haven't taken it for a spin yet but it definitely has a lot more pressure.



It also seems like the banjo attached to the MC is a little bit wet on the bottom, and a tiny bit has seeped out around the cap. This is most likely because we may have put in too much fluid, and the sun has been beating on it all morning (it's 11AM now, already in the 80's F, erm I Think that's 26.6 C, and it only gets hotter). Don't think it's residual just because it's been sitting in the son, and it would have evaporated I think. I'll double check it to ensure that it's tightened. Brand new crush washers so it shouldn't be too big of a deal.



Should I bleed it using traditional methods before taking it for a spin, or using the "Shep method?" Or just take it for a spin first and see what happens?
 

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For what it's worth, I bought a brand new unit from a guy on Ebay in Florida that was for a 250 Ninja. It also said it fit a Honda CM450. It has the smaller 12.7 piston, which as you mentioned should give more 'squeeze' power. I haven't ridden it down the road yet, but around the driveway I can lock up the front wheel with just a little bit left till it would hit the bar.



I bought the bike non running and with no frt caliper. I have an identical year parts bike I took the caliper off of and rebuilt it. The masters on both bikes looked horribly sun beaten and it was going to cost almost 100.00 for a new rebuild kit and a new reservoir tank. The 250 Ninja MC was 34.95 plus shipping, but I had to wait 5 days and put my bid in in the last few minutes to get it at that price
My next step my be to get a new braided hose for 2 reasons. I think the one on there is probably the original and also it will keep the pressure up by not allowing the hose to expand and reducing the pressure that is supposed to be meant for the piston in the caliper!



Larry
 

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I think that it's just improper bleeding, as it's doing the exact same thing that my last MC did in terms of pumping the handle to get it to firm up a bit, and then waiting a while without using it'll lose pressure (When riding, not when sitting, and it still doesn't have near as much pressure or power as the last one..yet). Unless both MCs were bad and had the exact same problem. I should've just bought a Chinese MC when I rebuilt my current one, it would have saved me tons of cash. The only reason I didn't was because my friends and family kept telling me that I'd never be able to find parts for a Chinese one if it were to break. Sigh.



I still really haven't done your method yet though, Shep. That's saved for today. I've only done Mityvac and traditional methods so far. If your method doesn't work, and reverse bleeding doesn't work (I wish I would have learned of reverse bleeding sooner, it's so cheap and seems almost fool proof) then I'll put the old MC on and see what happens.



I just wish I could return the thing, but I've cut into it so many times he'd probably send it back to me and laugh.


We've all had frustrating jobs,not just on motorcycles




With Banjo bolt on the MC,fluid in the pipes and the bleed nipple open and a tube submerged in a jar of fluid or a one-way-one-man bleed kit.Fill up MC and a good load of spittle on your palm press on top of the MC and make a seal and slowly pump the lever?
 

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Discussion Starter · #25 ·
We've all had frustrating jobs,not just on motorcycles




With Banjo bolt on the MC,fluid in the pipes and the bleed nipple open and a tube submerged in a jar of fluid or a one-way-one-man bleed kit.Fill up MC and a good load of spittle on your palm press on top of the MC and make a seal and slowly pump the lever?




That's what I dub the "Shep Method" lol. I think I'm going to take the bike for a quick spin to see where it's at after having it tied overnight, and then do that. I'm afraid of making it worse, but I'm also paranoid so there's that too.



Or is it more advisable to bleed it before taking it for a spin?



I asked this in my aforementioned edit, but it looks like I edited after you had clicked quote. My mistake.
 

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[quote name='Cramer' date='23 April 2011 - 09:10 AM' timestamp='1303571400' post='64209']

it would have saved me tons of cash... [quote



I've had a lot to read here so If I'm making an echo... My Bad!. Sorry




the brake syst needs to be sealed... if it's leaking at all, it will never work consistently. I'd fix any leaks first. think of a hydraulic system as a liquid rod... the fluid does not compress and any leaks are going to compromise the strength of, and the pushing and pulling of this "Rod"



One issue causing this type problem can be a shot bleeder screw. If it is allowing air to be sucked back into the syst. I think I recall someone here advising teflon pipe tape.



These do get overtightened often, banjo bolts being over tightened is also a common issue. Get new crush washers, and do not put the gorilla wrench when re tightening them. I use a two or three finger "feel" method when I do not have a proper torque wrench...



I Would not even begin to try and service these brakes without a vacuum device of some sort. I use a big syringe.



Another Caveat is do not use new brake fluid from a previously opened container. Brake fluid will absorb water from the atmosphere and is compromised over time after being exposed to air. Start with a brand new un opened can of fluid. ( even the smallest bottle of brake fluid is more than twice what the bike needs, I dispose of a lot of unused opened fluid
)



It's expected that a few bubbles will need to be bled over a couple of days to get the syst completely air free... over night the fluid will settle out and any bubbles should rise to the top of the fluid column.



If your rotor is hot after a a couple blocks of riding and not using the brake, it is dragging.



Looking closely at the wear pattern on the rotor face it should be consistent... any big gouges, warping etc should be obvious.





I'll bet its that 3.50 bleeder screw causing the headache on this one






One question Cramer... how much is a "Ton" of cash worth these days
 

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Discussion Starter · #27 ·
Took 'er for a spin. Definitely much better than before, though I can tell either there's still air in the line, or it's just not building enough pressure. The first maybe 1/4 to 1/2 doesn't do much of anything, the last 1/2 still has braking ability. And as usual, pumping gives it more ability and more power. I was paying particular attention to try and locate some "pulsing" just to maybe rule out warped rotor. I don't know if it's really pulsing as described for a warped rotor, but sometimes (not every time) when braking and holding in the brake I was able to feel a very faint pulse at a fast rate....



Regardless, I'm going to go and check runout, then try the Shep method of bleeding, and ensure that everything is tightened properly.



If the Banjo Bolts themselves are bad, where would I find new ones? How do I determine that? They both were out and didn't look bad, but just trying to cover all bases. Bleed bolts I know that I can probably find at Autozone. I put Dielectric grease on the threads of the bleed bolt (only grease I had) to try and stop air from flowing in while vacuuming, but watching the gauge does show a very very slow leak, so maybe I should just use the teflon tape and see if it makes it better. About to go to tinkering now, I'll be checking this thread via my blackberry to read previous and any future suggestions.



Oh, and something else...I just read a post on the old forums...



If you have the round reservoir master cylinder, take off the lid. Pull the lever. If you get a little geyser of fluid, that's the problem. On that design, you can lose the first half of lever travel because no pressure is being built up in the line, rather just gushing back into the reservoir.


I know that I don't have that Master Cylinder, but this one does squirt a little geyser each time squeezing the lever, of course with no lid or anything on it. Is this normal? My uncle says that it's just the piston closing the return hole or something. I see no other mention of this being a problem, but remember, I'm paranoid...haha.
 

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Believe it or not I've seen a run of defective crush washers at an auto parts store, every one of them wasn't perfectly flat on one side. I just went to another store and the ones they had were fine.
 

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Discussion Starter · #30 ·
Using Shep's method seemed to make it lose pressure o.0. I tried it without my vacuum pump...maybe I did it improperly. What was supposed to be a day working on my front brake turned into a day working on my father's scooter, so I guess I'll try and do everything I said I'd do today tomorrow -.-. Sigh. Oh well. But yeah I put the tube from the bleed nipple in old fluid, and the very second I started pumping the MC with my hand over it it lost pressure. Now it's back to where it was yesterday. Guess I'll tie it to the grip again tonight.
 

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Discussion Starter · #31 ·
http://www.youtube.com/watch?v=dntWGopfknk



Just wondering if the sound I'm hearing in my very agitated youtube video is normal, or something to be looked into? I know I say that it looks like the rotor does move around a bit, but that's something I'm not really too certain on. It was too dark to really tell. That noise has always been there since the rebuilding of the caliper and original MC. It's always been the same pattern in hitting the pads. I really hope that you guys can hear it, my mic didn't pick it up too well.



Also, I'm going to try Shep's method again tomorrow with the Mityvac. If I do this, do I still need to work the lever, or should I just hold my hand on the MC, while the Mityvac draws a vacuum? I'm going to do everything I can to ensure that it forms a proper vacuum. Zip ties on the hose, teflon tape on the bleed nipple, the whole nine yards.



I think I did Shep's method improperly by not having the tube full of fluid, it only had an end in the bottle of fluid. Or if that doesn't make any difference, maybe it lifted up a bit or something. I've been frustrated lately, only partly because of this, so I've probably not been putting proper thought into things. I do better when I understand the exact mechanics (like what exactly the methods do, how those results will help me, etc) and I honestly don't know too much about hydraulic brake systems, so I think that my lack of research is also partly to blame.



Anyhow, another long winded post. Thank you all again so much for the help. I'll update you all on what happens or if I have an epiphany.
 

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Discussion Starter · #33 ·
Hopped on 'er this afternoon and all of a sudden I have usable pressure again. However, it still doesn't feel 100%, so more bleeding is in order....aannnnd I still have my original problem that made me start this thread to begin with. The more I travel, the less pressure there is. Pumping the handle makes it better for a little while. Ugh. I don't think it's this master cylinder as the last one did the exact same thing. Brand new SS line, so that leaves the caliper.



Well after thinking that, I had a chat with the friend that helped rebuild my caliper. He remembered a few rather important things that I completely forgot.



The anti-vibration shim that goes on the back of the pad on the piston side had its tabs broken off, and we kind of willed it in there to make it stay.



The pad spring that holds the two pads was put in by a hunch, as the manual didn't give any information on it, but it's in the position stated by a different manual that I just looked at...we're just unsure if it's upside down or rightside up.



I never thought anything of either of these two things, and completely forgot about them until I was chatting with my friend.



Could either of those two pieces be causing the original problem? I know that they aren't affecting the bleeding, but they may be causing the original problems. I don't want to go into the caliper again unless I either have a replacement shim, or I learn that it is unnecessary and that I can live without it. Then I can check that spring with ease of mind.



Maybe the problem was under my nose the whole time? I sure hope so. Anyhow, I'm off to bleed the system a little more, and hope I don't screw up and get air in it again.
 

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Discussion Starter · #34 ·
Double post, but it's relevant.



Spent like six hours today going in between Mityvac, traditional bleed (open valve, squeeze handle, close valve, release handle) and Shep's method. Maybe I was doing it wrong, but every time I tried Shep's method I'd lose all of the pressure that I'd gained. Mityvac and traditional bleed brought it up to great pressure...however, exactly where the old master cylinder was! Ugh. Same ol' problem where it loses pressure after going down the road for a little bit, and pumping it up brings it up to a better pressure. I figured it may have still had air in it, but hell it's so late I just tied it to the grip and called it a night. Also did a lot of pushing the piston back to try and knock some bubbles out, it seemed to help a little bit too.



Is the losing pressure thing a symptom of air still being in the line, or do I need to take a look at that shim and the pad springs? If it's a case of air still being in the line, well I guess that's dumb ol' me for wanting to replace that old MC without trying to bleed it first (though it did have a leak in the top of the reservoir still, and it did need a new brake light switch). If it's something else, well then shame on me for not considering to look at those parts in the caliper first. I thought that we had rebuilt everything, but those two things weren't in the rebuild kit.
 

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You showed a video, although it was quite dark and nothing could be seen. How about you show a picture of your bike, or more specifically, the handle-bar area where your M/C is sitting. This could help out a whole lot in trying to solve your troubles.
 

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Discussion Starter · #36 ·
The purpose of the video was for the noise only. I only have pics of the bike with the old M/C on it at the moment, I can take more tomorrow if necessary.





I googled up a thread in which someone was describing the same problem, and it turned out that they had a shim that was binding. Since my shim didn't have any tabs on it, it wouldn't surprise me if it was binding. I just don't want to take the caliper off and not be able to put the thing back in if it'll cause any problems. Can I safely go without it? I don't care about brake noise, though if it'll affect braking performance at all then I'll just leave it until I can get a new one.







The windshield isn't on at the moment, if that makes any difference. Those are Daytona bars.
 

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Is that a Memphis Shade? That company likes some robust brackets for their windshields. Wish the other companies would learn.
 

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Discussion Starter · #38 ·

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There MUST be a divit or crator where the tabs ride on the caliper and "catch", thus causing a bind that acts like a return spring when you release the brakes, thus causing the pads to "push-back" the cup much FURTHER then it would if it wasn't binding. Which is why you have to keep pumping them up after you haven't used your front brake for awhile. Perhaps pulling the caliper and filing away where the tabs ride would smooth things out for ya.



Hope this helps.
 

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Discussion Starter · #40 ·
So you're saying that it's natural for it to lose pressure overnight or after a few hours or something? I'm saying that the spring should be in the caliper correctly, but it's possible it isn't...but the shim that sets in between the pad and the piston didn't have any tabs on it at all, and it was extremely awkward to get it to stay in place when putting the caliper back together. I forgot about this until yesterday when talking with my friend. I think that that may be the cause. I was asking if I could ride without the shim, but that's now a moot point.



I was about to order on Bikebandit for the part then realized that the front end I ordered for my CX500 a few weeks ago came with a (apparently) complete caliper! Time to take it apart and see the condition of its shim and spring. I'll be doing that tomorrow (class, appointments, etc today so no work on the brake).



Anyhow, last night after getting it to build up the best pressure I've ever had it at, I tied the lever to my grip. This morning the grip was perfect...better than I've ever had a brake on this bike before, and it stopped me much faster than the last one. However, going down the road did indeed still lose pressure, and I had to pump it up to get full power, though it seems to be losing pressure at a much slower rate than the last MC and even at its lower pressure it feels like it has more than the last one did. So I'm ok with it for now, until I play with that shim.



Also, it may be my imagination, but even having it set without riding it made the pressure drop a little bit. This I'm not 100% sure on as I could have easily parked the bike with it having a lower pressure, and forgot about it. I'm going to pump it up tonight to the highest that I can get it (not going to use the zip tie) and then tomorrow morning I'll see if it still is as firm.



So, if switching the shim doesn't fix it, should I just try bleeding it a little more the traditional way and see what happens? I'm almost positive it isn't this MC...I mean, the last one did it. At this point the only things that haven't been replaced are the banjo bolts, the shim in the caliper, and the bleeder screw. Even though glancing at the Banjo and Bleeder showed that they were in good condition, maybe it isn't so.



One last thing, I've been hearing a lot that DOT4 would be better for the system because of the higher boiling point, and my rather fast riding style (fast but safe. Only aggressive when there aren't other people around that I can hurt). Would it be a wise idea at this point (considering that I need to buy more fluid anyhow, and DOT3 and 4 are the same price) to bleed the DOT3 out with 4? I don't care about losing the money I put in the DOT3 if the DOT4 could help and wouldn't hurt anything (or hell, if I could mix them, I'd do that too).
 
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