Will brake lines fail? New/leftover rubber lines?

While the bike is apart I am analyzing replacement of various components. Regarding brakes I am reading recommendations and found an old post here which suggested that I may gain 99% of the performance back by replacing only the cylinder to caliper hoses. That appealed to me greatly but I need more solid information.

1) What do you think of that idea?

2) Is there a possibility of a catastrophic failure in an original hose, meaning they all must be replaced? Have you heard of this happening? I know some of you have owned bikes for 30-40 years and thus you can share lots of events or perhaps no events whatsoever.

I am not crazy about braided lines. I do not see the need for me to upgrade this particular bike for myself. This brings up the other point: Are new/leftover OEM brake lines acceptable? I would think they would be a good change from 17 year old used lines but would still have aged and begun dry rotting. Thus I am left with no idea of the overall value or smartness of using them, other than some anecdotes of bikers who never hesitate to use them.

I am not a miser so if you shot this down and the consensus is to replace everything, it is what it is. So fire away.

 

replacing the brake lines- go SS

 

It's probably the ozone and UV rays from the sun that do most of the damage to brake lines, IMO anyway. So NOS should be okay. OTOH you'll probably spend almost as much replacing brake lines with NOS as you would if you replaced with SS lines. Bike Bandit shows the OEM clutch line as around $63, and also unavailable. So if you replaced just the lines from the master cylinder on the front and rear brakes and clutch, you'd be looking at nearly as much as a complete set of SS lines would run you. No savings dollar-wise, and no increase in the "Bling" factor. JMO anyway. And replacing with used parts is just plain silly.

 

I didn't understand the "used parts" reference though. Are you calling NOS used? Or making another point?

 

"which suggested that I may gain 99% of the performance back by replacing only the cylinder to caliper hoses"

Nope, unless your lines are 99% constricted. In which case you'd know because the brakes would not release.

The majority of line decay is usually on the inside, due to badly contaminated fluid. If you've kept up on flushing the fluid, this is a total non-issue.

Line failures due to "popping", especially on a motorcycle, are almost unheard of. Keep in mind these are the same type of crimped lines used on much larger vehicles, under much higher pressure.

SS lines are great, but if you've ever done the initial bleed on a set you know what a nightmare they can be. This is because the passage volume is much less than factory lines.

To sum it up, leave them alone. If anything you want to lean toward the OCD side on fluid replacement.

The condition of the calipers/sliders and mechanical bits should be of primary concern, much more so than the lines.

 

It should say "get back 99% of the lost performance."

So there is not any significant loss in this system given the parts are far more robust than required? Makes sense to me, so now I'm now leaning toward your advice.

The bike came with crystallized fluid in 2014. Now did I lose too much pipe volume due to decay?

Fully flushed, reservoir scrubbed, calipers rebuilt, one riding season later it is now round 2. I had originally told the mechanic to again purge a large amount of fluid through the system, particularly the proportioning valves (CandyRed had mentioned how these will be gunked up and nigh impossible to remove and clean.) So am I back to OCD status after this? Or should I have concern for line decay? I am sure this bike sat for years with the old fluid.

 

Loss of volume is not an issue, until they swell shut lol.

Yes great point about the potential blockage in the prop. valve, but again a line replacement will do nothing to improve that situation. If your brakes feel spongy, first line of order is a bleed. If that persists then you have reason to suspect inner layer swelling. Near-worst case scenario is, if the inner layer is breached, it will create a bubble in the outer liner. Which will be obvious because you will have almost zero brake pressure.

If your lever and pedal are firm, but you feel the brakes overall are still weak-ish, then it's time to look at new/better pads, and consider rotor resurfacing or replacement.

 

No I am very pleased with the performance. Granted this is my very first bike so I have no relative comparison. But my initial thoughts were, "Why do some people here complain about the brakes on this bike? They seem to stop this 530 lbs quite well!" The rear has plenty of power too and keeps the bike well balanced. I have no issues whatsoever. Just trying to do right.

Yes have new pads new too, I left that out because I figured it would be obvious for an overhaul..but yes you never know who you are talking to.

 

I don't always adhere strongly to the IIABDFI philosophy, but in this case I do.

If you're happy with the brakes, put your money and energy elsewhere. Creature comforts, more flashy stickers, that sort of thing

 

I tend to disagree with the position that the brakes lines fail from the inside out. I stand by my original statement about sun and UV rays. But you can actually see if your lines are soft since they visibly swell under pressure. New lines won't. Watch closely, or close your fist around the line and you will feel the line swell when you close the brake lever fairly hard. IMO if the bike was stored in the sun, the lines will be in worse shape than if it was stored inside. But JMO of course.

No, I was sure you were talking about NOS, but just wanted to put out there what I thought of putting on used parts.

 

I don't disagree with any of that either FJ12, as there are so many variables.

Here's another opinion- http://www.carsdirect.com/car-repair/when-should-you-replace-brake-lines

 

The prior owner said he kept in in his house. While his lack of attention makes me question everything he said, aside from some scratches the exterior looks like brand new. I do not see any evidence of bleaching or weathering on any of the exterior surfaces.

Thanks for the tests as well. It is always a good idea to test now and make determination later.

 

The object of braided hydrauic lines is that they do not swell and are not "rubber" . I hope the braiding (stainless steel) is coated on both sides.. Some shards of stainless steel wire in a brake like could really get to be a problemo in a hurry.

Best thing for Knight The Noob is to maybe sell the bike or get some training wheels.


https://www.youtube.com/watch?v=f6sw39pPrr8

 

Gad wish I hadn't read that scary story. It does seem to reinforce that a bad condition would result in either binding or mushy feel, making the condition obvious. The bike passes all of these tests so just a physical check of bulging left.

 

Rubber lines won't fail, they just expand more - making braking weaker and less feel through the lever.

 

I've never heard of motorcycle brake lines bursting, so I would not worry about that part. In my experience rubber lines do become more flexible with time and so some of the hydraulic pressure from your hand goes to expanding the line slightly, which makes for a spongier feel that no amount of bleeding can fix. That is where braided lines come in as they have much less elasticity, so you get a firmer brake feel. In the end it does come down to what you prefer or know, as to whether you like a softer feel to the brakes or something firmer. Neither will make the bike stop harder or safer.

 

I agree with the idea that the lines won't burst. I've never even heard of that happening, so it's pretty much a non-issue when it comes to whether to replace lines or not. To me it's strictly feel and modulation.

Oh yeah, and looks. :eagerness:

 

my 86 750 had all original lines on it when I got it in 2013. I saw no obvious signs that they were going to fail at any point. No cracks or anything. I went ahead and replaced them with stainless braided anyway. Brake feel was a tiny bit more solid after the upgrade. I'm not replacing the OEM lines on my 99 anytime soon though.

 

Braided lines are also cool and are good for picking up chicas. They can't resist a line like. " I have braided lines".

 

Ok, well hell might as throw out my thoughts, LOL FWIW BB will surely counter. When it came time reworking the brakes the lines on prior no linked brakes, where replaced with SS Braided, only for if nothing else ha-ha they cost less, then looking at what gains there are in no pressure loss and or a feel. made it a no brainier, But that's on bikes that had standard brakes. These linked brakes, as It just so happens, I have the front off and have been thinking of doing a SS line job. No F'n way, what the Hell, what a freaking spider web. Grrr *&^%! Honda, so until I get in the mode for a de-linking, and have all the parts the stock lines are staying put. But the SS lines IMO definitely add a better feel but then I have a lot of experience and know what I'm looking for, why I'm weird-ed out on this 5th gen. I feel its going to take a while not using the rear brake....much.... So if one doesn't know, then probably better left alone.