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Discussion Starter · #1 ·
My 1974 CB450's previous owner told me (among a great many other ridiculous things - I'm thinking it'd be nice to have a central collection of bs previous owner 'knowledge' we've all received) that he'd "had to back out the bleeder" because the 450 calipers were so prone to freezing up... He seems to have kept riding it that way, including after the bleeder fell completely out, thus allowing the caliper to sit with mud and rain water for a year or two before I got it cleaned up.
My confusion is that I got the brake to be pretty functional, for an entire year, by getting the piston removed and doing what I could to polish the caliper bore and the piston. With gray scotch-brite. I even reused the old seal. The metal's not perfect and it leaked a little, but still worked. A year later (that would be all of 2010), after I even tried to flush the brakes before storage (bled them until clean fluid came out the bottom?), it's been really really soft all year. I took it off and there had been enough leakage to attract lots of what I'm assuming is dirt and brake dust to leave a whole lot of black and purple goo around the pad. I cleaned it as much as I could, and several re-bleedings haven't made much of a difference.
Question - What are the chances a new piston fixes this? Thanks a million to anyone who's got any thoughts on this (pictures should be below)
 

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If the caliper won't let the piston back off the rotor, it's possible the bead that the seal sits on is corroded. Cleaning helps but if the corrosion is too deep the profile is lost and the seal won't have anything to help it straighten out when the pressure is released.
I'd say that piston is toast, but I've heard of people using JB weld to fill in the pits and sanding smooth. :?
Usually by the time the piston starts looking rough, the lines are bad too, they deteriorate on the inside, and deposit a lot of particles into the fluid. If the lines deteriorate too much they can't handle the pressure, expand and the brake feels soft.
 

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I think there is a good chance you'll fix the problem with a new piston AND seal. But why stop there? Those little pinching things keep you from hitting whatever is in front of you. Do whatever you need to do to restore the brake system to fully functional. Even if it costs $200 to replace/rebuild everything isn't your life worth that? Sorry to be preachy but....
 

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+1 on the piston being toast,

and also +1 on not the place to save a buck, new piston and seal, nice line with properly working master also :D :D
 

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Discussion Starter · #5 ·
thanks everybody. points are all well-taken; i'll start with a new seal and piston and report back. in the meantime - can the average auto parts store crimp new fittings and build some replacement brake hoses, or is that going to be a specialty thing?
 

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www.z1enterprises.com has nice braided stuff with all the fitting you would need. Or someplace like Oldbike barn. If you auto store is a real good one, they might have the stuff.
 

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old bike barn can be pretty sketchy, good luck with z1 though.
 

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I like Z1, I've ordered from them several times, and never had a problem, and the prices are good.
 

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+1 on the new piston and seal. A nice new rubbery seal allows the pads to retract so they don't get the Honda squeal as easily.
Find a local hydraulics shop that is a Goodridge dealer. they can most likely assemble a custom fit hose for you. While yer at it, scrap the union that has the pressure switch in it(at lower triple) and get a continuous line from master to caliper. Have the hydraulics shop order you a banjo bolt that has the pressure switch built in. Cleans up the front end. Remember, the Honda threading is different from usual on that banjo bolt.
A braided line makes a brake out of the Honda "slower downer". Still sketchy in the wet, though.
If, you can, have the disc bead blasted to remove several decades of glazedness.

NE
 

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Discussion Starter · #10 ·
Wow, yeah, thanks. Makes it sound like a no-brainer. I've had a semi-non-functional front brake for so long I'll probably have to re-learn some stopping skills. I'll try to figure out how to do exactly what you're suggesting. With z1enterprises prices, 37" of hose with two female thread fittings, plus a male-thread banjo fitting for the master cylinder and a brake line adapter for the caliper, looks like it's going to be about $40 ($25, 10 & 5, respectively). And the banjo bolt/light switch is another $15, plus $10 and a few days for shipping. $65 sound pretty fair for this, but I'll see if I can find someone in Columbus, OH who can do it for less (crimped fittings would at least be neater, and probably simpler, yes?). And, more importantly, locally would also likely happen more quickly....
 

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Discussion Starter · #11 ·
okay, good news. and thanks to everyone for pushing me to spend some money on this. my front brake works now.
first thing - i called all of the hydraulic related businesses that google told me were in or near columbus, oh. 5 'no' answers and 3 voicemails... one of which was returned, with a 'maybe', but only after i got impatient and just placed an order with z1enterprises. i was hoping it would have been easier and simpler to assemble...
but the outcome is that i was able to order a threaded banjo fitting, a single hose and an adapter to go from the hose straight into the caliper. very simple, and now i have a front brake! (also, z1enterprises is AMAZING. i was a bit of a customer service nightmare, and they were super patient and nice and responsive. i'll continue to buy as much from them as i can.)
also, i got one of the phenolic brake piston's that i've seen discussed here and elsewhere. $42 delivered, as opposed to $90+ for the stainless ones, and so far so good.
Here's another question: the adapter to connect the hose to caliper had a more pronounced taper than would a normal brake pipe flare (is it still an SAE flare even if it's a metric flare nut? the old brake line didn't quite look like a bubble flare, but i've never seen an iso that wasn't sitting in the auto parts store's rack...). The inverted flare in the adapter looks like it's maybe 45 degrees; the convex part inside the caliper looks like it's a bit flatter, maybe 37... There's no leak, but do I need to worry about this? How closely do the flares need to match?
 

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brake lines are double flared, there are a couple different standards, and probably many possible outcomes based on your tool quality. If it is not leaking I would pay it only the standard pre ride check.. (check for fluid level, leaks and lever feel.) I would say that having a slightly off flare is very unlikely to cause a sudden catastrophic failure
 

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Discussion Starter · #13 ·
Thanks! That is SO much better than most of the alternative answers I was anticipating.
 

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I bought a tubing flare kit from Harbor Freight, and made my own replacement part. The single flare is holding up fine.
 

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Brown Bomber said:
I bought a tubing flare kit from Harbor Freight, and made my own replacement part. The single flare is holding up fine.
At the risk of inexperienced "do it yourself mechanics" reading this, I'd like to state that a single flare is unacceptable for a brake line connection. I doubt you'll have a catastrophic failure but it's not a question of IF it's going to leak, it's just a question of WHEN.
 

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+1 to the NEED for a correct double flare.......
 

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Discussion Starter · #17 ·
Hi, I think there are several points of confusion right now (most or many of them mine, or at least my fault).

First - As I understand it, there are two main sorts of brake line flares (not counting whatever 'british' is). One of them is SAE, where the brake line is flared 'out' from its centerline at 45 degrees, and then folded back on itself to double the thickness of the part that is flared. It looks like a martini glass with double-thickness sides. The other flare is ISO, or 'bubble', where the material is flared 37 degrees and, instead of folding the material all the way back on itself, it comes back together just enough for the end diameter to be back to normal. It looks more like a port glass. (Please forgive the visual metaphors). I have a fair amount of experience with SAE flares and comparatively none with ISO. SO...
Question 1: Is all or any of this correct?
Question 2: Do both of these count as 'double' flares? (which I assume is the case, since a 'single flare' would be more along the lines of what we'd expect in a lower-pressure application).

Second - More to the specific point at hand; I would only ever use one of the foregoing (the british thing notwithstanding) on hydraulic brakes. The trick is to determine which I have and/or which I need. In this case:
Question 1: Am I correct to assume that only a North American product would need the SAE and, on that basis, I need an ISO flare? Similarly, can I assume that if the flare nut thread is metric then the flare must be ISO?

Third - The fitting I'm talking about having bought and installed is, I believe, stainless: www.z1enterprises.com/detail.aspx?ID=3349. The picture shows the side that goes into the hose. The other side of it has an inverted flare, and that's the issue at hand; I'm not sure I know how to look at a flare and know what whether it's designed for SAE or ISO (Incidentally, I've asked z1 about this, and will likely get an answer from them that will help with this).
Question 1: Does it matter what material is used to make the flare? Does soft steel need to 'smoosh' a little to get a seal in a normal setup?
Question 2: Is there any way to measure a flare?
Question 3: In short, this is what I've got. Will it work?

I'm sorry for such a long post, but I wanted to try to articulate everything I'm using as 'knowledge' and guesswork. In hopes, that is, of hopefully connecting all the dots.

[also, completely unrelated to all this, I want to be a good citizen on the message board - should we keep the picture posting to a minimum to save space? pictures are important for diagnosis and bragging, i know... i'm removing the piston pictures from earlier either way, to save visual space, but does anyone have a sense of whether uploading files is something we should minimize?]
 

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That adapter has the correct flares for its ends.....We are discussing the flare on the tubing side which attaches to the "near" (left side) end in the pic...THAT tubing is the part that needs the "double flare".......
 

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Discussion Starter · #19 ·
Okay. The near side of the fitting, as it appears in the picture, is the one that attaches to the (rubber coated) hose. The other end, the one that's not visible in the picture, is the one screwed into the caliper. It has an inverted flare that looks, as one single piece, like the end of a conventional flared brake line with a flare nut on it. The question is whether it is 'exactly' like a conventional brake line, or at least enough so that it will work.
The original setup, of course, had two rubber hoses on either side of a light switch and a metal line to run into the caliper. That was 3 banjo fittings, a switch, a rubber-to-metal union, and a flare nut. If I were replacing that straight up, I'd of course get an ISO flare with a 10 x 1.25 flare nut to connect into the caliper. Except I'm hoping to simplify the whole thing, with as few pieces as possible - so I want to know if I can use this fitting on the end of the rubber hose (both the hose and fitting are Goodridge products) instead of having a rubber hose connect to a metal brake pipe which is then connected to the caliper. I want to eliminate the metal brake line. Will that work?
I'm sorry that I'm struggling so hard to ask this question...
 

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Yes, I too have problems translating the "picture" in my brain to words....BUT, I got ya now..... Yes, it should work fine IF the hose can clear the fender brace, or you re-route it somehow so it is STILL supported in a clean arc so the hose flexes properly (not into wheel, tire, or engine) when the suspension compresses and extends...
 
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