Not an oil thread but should be just as good as one... per the Yamaha TDM850 service manual, "change your brake hoses every two years and your brake fluid only when your brakes are dissembled".
:Facepalm:
So the question begs, how often do you replace your brake hoses and fluid?
(http://fjowners.com/gallery/10/2200_12_01_17_11_40_37.jpeg)
My 82 Suzuki still has the original hoses, oh my!
IIRC, on the FJ, Yamaha recommends to replace the brake lines at the 4 year mark. I did mine back in '89.
I don't have access to my manuals, can someone check my memory on this? ^^
I run DOT 5 which does not absorb water (non-hygroscopic) and I live in a dry climate, so I flush the systems out every 2 years. Because DOT 5 is lighter than water (floats on water) I unbolt and flip my calipers and clutch slave upside down and zip tie them a day before I flush, that way any accumulated water will pool around the bleed nipples. While holding them upside down, open up the bleeder and out comes any water.
I've noticed that after wet weather riding, for some reason water can and will accumulate in the clutch slave, not so much in the R-1 calipers.
On DOT 3/4 which absorbs water, you don't have to do this.
Any water in the system will be suspended in the fluid and thus, will flush out with the fluid.
Quote from: 1tinindian on January 12, 2017, 12:29:41 PM
My 82 Suzuki still has the original hoses, oh my!
My 84 FJ also has the original hoses which are working just fine by the way.
Dave
Quote from: Dads_FJ on January 12, 2017, 11:56:09 AM
So the question begs, how often do you replace your brake hoses and fluid?
A good way to remember when to change the brake hoses on your bike is to do them the same time you replace them all on your car (and disassemble wheel cylinders/calipers and master cylinder for cleaning, flush fluid and replace, remove and scrub discs etc)
Noel
Yea, 3 things could have occurred....
1) those Yamaha engineers are idiots.
2) Yamaha folks are greedy bastards who just want to sell you parts
3) Yamaha's legal counsel advised them to say that to cover their ass.
Really, the oem rubber lines are good for twice the length of time they recommend....no wait... I mean the oem lines are good for 10 times the length of service life they recommend......just round it up to the life of the bike of the bike, just like all the other rubber parts. Remember, it's just the brakes.
You got 30 year old tires with good tread on them? Look fine on the outside? No problem!
You feeling lucky today?
Just thinking aloud on the DOT3/4 brake fluid and the water it may absorb and the scary idea of ones brakes becoming non existent if and when that water should come to boil. Now, if the brakes are being applied, hard, it is possible (as I recall from trade school theory) that hydraulic pressure can go as high as 1,000 psi. Under that pressure, at what temperature does water boil? Will it boil at all if it has become one, chemically bonded with the glycol base of the brake fluid ? With glycol coolant, the boiling point is higher when cut 50 % with water. Further, if the DOT 5 fluid does allow the water to remain intact, why is there no fear of it boiling in a caliper ?
Cheers
Simon
Quote from: Pat Conlon on January 12, 2017, 08:38:38 PM
Yea, 3 things could have occurred....
1) those Yamaha engineers are idiots.
2) Yamaha folks are greedy bastards who just want to sell you parts
3) Yamaha's legal counsel advised them to say that to cover their ass.
Really, the oem rubber lines are good for twice the length of time they recommend....no wait... I mean the oem lines are good for 10 times the length of service life they recommend......just round it up to the life of the bike of the bike, just like all the other rubber parts. Remember, it's just the brakes.
You got 30 year old tires with good tread on them? Look fine on the outside? No problem!
You feeling lucky today?
Whoaaaaa.... Who got off the wrong side of their FJ this morning. :biggrin:
If brake hoses become US from use they should, if anything, be changed
more frequently on cars than bikes.
And no Pat, luck doesn't come into it and I don't have a cavalier attitude to brakes, but I do have a lot of experience.
Noel
Noel, are you aware of Any car manufacturer that specifies a 4 year service life on their oem brake lines?
Didn't think so. Still, you keep comparing motorcycles to cars.
Change your bike's oem rubber brake lines when you change your car's is bad advice and certainly not the advice of experts.
Quote from: Pat Conlon on January 13, 2017, 11:04:53 AM
Noel, are you aware of Any car manufacturer that specifies a 4 year service life on their oem brake lines?
Didn't think so. Still, you keep comparing motorcycles to cars.
Change your bike's oem rubber brake lines when you change your car's is bad advice and certainly not the advice of experts.
No I'm not, nor any other motorcycle manufacturer. Nor am I aware of any brake hose manufacturer who does. Yamaha don't even make their brake hoses and I'm not aware of any hose manufacturer who specifies 4 years. I suspect the likely origin of the 4 years is the hose makers have given Yamaha an already conservative number and they've halved it for good measure.
I use cars as an example because they are around in larger numbers, do higher mileages, the fleet is considerably older and the hoses operate in a harsher environment. This makes it much easier to gauge longevity and the rate of breakdown before becoming unsafe.
As I said, if anything, car brake hoses deteriorate faster than motorbike hoses.
Pat, I was a Licenced Vehicle Tester for many years. This is a Govt issued licence for the purpose of carrying out vehicle inspections and issuing Roadworthiness Certificates, a legal requirement with every change of ownership and vehicle registration. This is no kick the tyres quickie inspection. It is a couple of hours work in a well equipped workshop. I have inspected thousands of cars and hundreds of bikes. The inspection is over the top to the point of being ridiculous but even so, brake lines were (and still are) only subject to a visual inspection.
The most worrying motorbike brakes to me are some of the routing, clamping, abrading and lengths of owner fitted braided lines I have seen.
Pat, I think you and I will just have to respectfully agree to disagree on this one.
Noel
Quote from: ribbert on January 15, 2017, 08:02:04 AM
......I suspect the likely origin of the 4 years is the hose makers have given Yamaha an already conservative number and they've halved it for good measure.
Ok, so if Yamaha halved a conservative number (Yamaha specifies 4 years) that conservative number is 8 years, say the brake hose manufacturer's halved their number (8 years) just to be safe, so the actual service life number on the hose is 16 years....? Let's add 10 years to that, just because, make it 26 years.
Noel, as an expert LVT, do you not agree that 30 years is just a 'tad' outside the service life of the oem rubber hoses?
In my signature line, I advise changing the oem brake hoses because they are over due for replacement.
I stand by that statement and I'm not standing alone. I have a lot of company saying the same thing.
Lastly, motorcycle brake lines have UV exposure, something cars don't have.
Quote from: Pat Conlon on January 12, 2017, 08:38:38 PM
Yea, 3 things could have occurred....
1) those Yamaha engineers are idiots.
2) Yamaha folks are greedy bastards who just want to sell you parts
3) Yamaha's legal counsel advised them to say that to cover their ass.
There is a 4th possibility... The number in the manual is a mistake. It's not the first mistake I've found in the FSM.
I will agree that a 2 year service life for brake hoses is overkill. But no more than 10 years, certainly.
Bill
QuoteJust thinking aloud on the DOT3/4 brake fluid and the water it may absorb and the scary idea of ones brakes becoming non existent if and when that water should come to boil. Now, if the brakes are being applied, hard, it is possible (as I recall from trade school theory) that hydraulic pressure can go as high as 1,000 psi. Under that pressure, at what temperature does water boil? Will it boil at all if it has become one, chemically bonded with the glycol base of the brake fluid ? With glycol coolant, the boiling point is higher when cut 50 % with water. Further, if the DOT 5 fluid does allow the water to remain intact, why is there no fear of it boiling in a caliper ?
Cheers
Simon
Simon,
I'd have to pull out an old text book to find you an exact answer, but the boilers at work were about 650 psi and the feedwater temp was around 500+deg F.
The thing to remember, when pressurized water above 212 deg F suddenly experiences no pressure, it flashes to steam and expands about 1000 times. In a brake system, as soon as you release the brake lever, the brake fluid/water wouldn't be under 1000 psi.
I don't think the water bonds with the fluid as much as it mixes into an emulsion.
As far as changing brake lines, I usually sell the bike before the lines need replaced :sarcastic:
If something is hygroscopic that means it mixes or bonds with water (usually bonds water by a meaning of hydrogen bonding or van der Waals forces). It does not create an emulsion. Emulsion is a type of colloid in which 2 phases never mix, but are dispersed in one another in a form of small droplets (u can make it with oil in water if you shake vigorously, but leave it be and soon you will again have two distinct phases).
That is true for water boiling what you said. But that would assume water is a separate phase in DOT 3/4/5.1, what it isn't. It is mixed and hydrogen bonded. The fact that boiling point is lowered with more water in the fluid remains. So I suppose the thing you talked about would happen, but with a slightly different variables (temp and pressure) than for a clean water phase. I did see a flash point temperature noted on the brake fluid casings.
Recalling a project first proposed by Jeff Hoffman (which he never got around to doing), when time came for my son to do a 6th grade science project we chose to boil brake fluid.
I've lost the data, but we had a control specimen which was a sealed container of DOT 3 fluid. During the test, we diluted the fluid with varying percentages of water, mixing it in and allowing a period for it to stabilize and absorb. Something like 1%, 3%, 5%, 10%, and 20% solutions were tested. One other thing we did was pour an amount of fluid into an open container and let it sit in the garage for about 2 or 3 months (thus allowing it to naturally absorb water from the atmosphere).
When time came to do the boiling, I was kind of amazed. First we boiled the control sample from a factory sealed container. It was cheapo Walmart DOT 3, but as I remember, it didn't actually boil until about 450 degrees F! By that time it was smoking quite a bit when it finally boiled. This was all at atmospheric pressure. Boiling the various samples, we plotted a curve of boiling temperature versus %water contamination. Again, the details escape me but I remember that it only took a small amount of water contamination to significantly reduce the boiling temperature down into the mid 200 degree F. Anything above about 10% contamination basically had the approximate boiling point of water.
It was kind of neat to identify where the open container fell on the curve. Being exposed to the atmosphere for a few months the fluid had absorbed about 8% water which was significant in affecting the boiling point.
That is way cool info, I will use that in all my future brake fluid dissertations! Tell your son he is being quoted!
Quote from: FJ_Hooligan on January 17, 2017, 08:58:58 PM
It was cheapo Walmart DOT 3, Being exposed to the atmosphere for a few months the fluid had absorbed about 8% water which was significant in affecting the boiling point.
Another good reason to go with silicone oil, besides what standard brake fluid will do to paint and some plastics.
So, do we assume that glycol based fluid is hygroscopic by accident? I still am not sure how the DOT 5 stuff deals with the presence of water. I always thought the implication was that water suspended was somehow less a threat than water collected in a pocket. I guess it's hard to know if there's enough water present in your DOT5 system at any given time to be a problem.How much water can you expect over how much time? In any case in 50 years of driving, I have never had a problem caused by boiling brake fluid. I hope it stays that way.
Cheers
Simon
I have seen brake fluid boiling only once, and that was in a rally car that I was navigating in, after a particularly difficult stage. And I must say we had the discs glowing pretty well too.
Mark
Simon,
I have several DOT 5 data points for you.
When I changed my FJ over to DOT 5 in the late 80s the fluid in the front brake system wasn't drained or flushed for about 14 years. The only reason it was eventually changed was when I converted the front end and installed monobloc calipers around about 2002. Disassembly and inspection of the stock calipers revealed no corrosion or deterioration.
The DOT 5 fluid lived untouched in the monobloc calipers until last year when I decided to flush it to clean a sticking piston (unrelated to the fluid). The DOT 5 looked just slightly discolored from fresh fluid.
Also back in the '80s when I originally swapped the brakes, I also converted the clutch slave to DOT 5. To this day, I have not touched the slave cylinder. The DOT 5 fluid in there is almost 30 years old! Perhaps its time to go ahead and change it?
I think the key is since DOT 5 doesn't absorb water it is "dry" when it is installed. If you take care and don't accidently spill your beer into the master cylinder, the fluid remains uncontaminated since there's no magic force that's trying to driving water into the system. Brake systems are sealed, water doesn't typically penetrate the system unless there is some kind of seal fail. For the clutch slave that happens when the slave seal fails and allows water to start contaminating the fluid and rusting the piston. Another interface is the master cylinder cap gasket. I've seen fluid on the outside of this gasket many times. If fluid can get out of the system, then air can get in. It you have a fluid that attracts water this is a likely interface. If you have a fluid that doesn't attract water, then even if there is interaction at this interface it doesn't necessarily cause water to condense into the fluid and contaminate it.
Or, I've just been lucky multiple times with DOT 5? Maybe I should buy lottery tickets. :-)
Quote from: ribbert on January 15, 2017, 08:02:04 AM
Pat, I think you and I will just have to respectfully agree to disagree on this one.
Noel
Pat, it appears my diplomatic attempt not to pursue this topic failed.
The average distance travelled annually by cars in the US is 15,000 miles, motorbikes – 1500 miles (Harley's apparently only average 1150 miles per year, or so they claim!)
So, cars on average travel 10 times further than motorbikes.
Say a manufacturer recommends changing the hoses after 6 years, a common and conservative number, then convert that to distance based on average vehicle use and you get 90,000 miles!
To travel 90,000 miles at the rate of 1500 per year (motorbike average) would take 60 years. That places them at about half life at 30 years!
Brake hoses become unserviceable for two reasons (excluding damage), rupture and rust. Rust does not cause failure but slowly reduces efficiency of a long time, it clogs the metal end fittings.
Excluding damage, eventual rupturing is attributed to normal wear and tear while in use. Heat, bending, twisting, pressure cycling and whatever the road throws up at them, in other words, use. That's why they fail near where the hose joins the metal fitting at the wheel end, where they flex the most, not from sitting in the garage.
No doubt hardening and cracking in the outer protective sheath is going to compromise the hose strength. To what extent the Sun contributes to this is pure speculation but you see a lot more of it on cars than you do on bikes, and they are never exposed to UV's.
I am still of the opinion that car brake hoses have a much harder life per mile than motorbike hoses, for many reasons.
And while we're at it :biggrin: my long standing objection is
not suggesting the hoses don't need changing, it's putting the fear of God into people about the danger of not doing so based purely on age.
Rubber hoses don't "burst" (excluding damage). They swell, they weep, they leak, all over time, and if entirely visible brake hoses and a sight glass on the M/C don't alert you to that, maybe you should get someone else to service it.
For the greater motoring public, brake hoses have always been something that is replaced when signs of deterioration are observed (this generally does not happen quickly)
The mileage and time over which this happens is so varied it's difficult to establish a trend. I don't recall ever being asked to replace a set purely because of age and without failure symptoms.
This is entirely my opinion from observation (and I doubt there are any figures available to verify/dispute it) but I believe a majority of vehicles will, after many decades of use and many hundreds of thousands of miles, end up at the wrecking yard or metal recyclers still wearing the brake hoses they left the factory with.
The oldest hoses that I know for a fact (family car) were never changed did 1,000,000 kms over 39 years on a Volvo.
While there will always be an exception to everything, a few years back the question was posed here on the forum for anyone who had ever suffered a brake hose failure on an FJ, no one responded. It was then extended to any vehicle they'd owned, still no answer (specific damage aside).
Complete brake failure is an extremely rare occurrence in modern times. Cars for many years have been required to have a split system, effectively two brake systems, motor bikes have this by default with separate front and rear brakes.
My point was, if you are going to advocate changing them on one sort of vehicle, you have to do it to the other, you can't differentiate between one and the other, they are subjected to the same conditions. It is the manufacturer who determines the life span of their product, it's up to the user to decide if and in what form they pass that on to their customers. Yamaha appear to be the only ones who do this. As you pointed out, no car manufacturer does and as far as I'm aware, no other motorcycle manufacturer does, doesn't that tell you something?
Quote from: Pat Conlon on January 15, 2017, 09:41:47 PM
I stand by that statement and I'm not standing alone. I have a lot of company saying the same thing.
Well, you got me there Pat, I don't have a posse, just me and the dogs at this end.
Congratulations on the new bike, any attempt to conceal your lust for one of these "Best of Breed" models ever since one passed through your hands a while back was a miserable failure – well done and about time!
To quote yourself on the subject "You'll love it" :good2:
Noel
I think I'll keep my opinion on brake fluid to myself.
Hey Noel, yes, this '92 I'm currently working on is one of the cleanest bikes I've ever seen... well cared for and at 31k miles, just broken in.
My last '92 went to Paul Lawson and it was a great bike, made better with my mods. IMHO the '91/92's (non abs) are the best of the breed.
My last comment on oem brake hose replacement is this:
There is a difference between anecdotal evidence and empirical evidence.Brake hose manufacturers use empirical evidence in the testing and certification (DOT,TUV,etc) of their product, and based on this empirical evidence, they come up with a service life.
Your experience with long lasting oem brake lines (e.g.39 year old Volvo brake lines) would be considered anecdotal (or subjective) and thus your opinion is based on anecdotal evidence.
I'll base
my conclusions on empirical evidence over anecdotal evidence any day.
I do value your insight and 0pinion, but yea, we will have to disagree on this issue. There is a reason for the manufacturers service life recommendations.
Quote from: ribbert on January 19, 2017, 05:50:22 AM
..... It is the manufacturer who determines the life span of their product, it's up to the user to decide if and in what form they pass that on to their customers. Yamaha appear to be the only ones who do this. As you pointed out, no car manufacturer does and as far as I'm aware, no other motorcycle manufacturer does, doesn't that tell you something?
No, you're wrong ^^ Yamaha is not the only motorcycle manufacturer that specifies a service life for the oem hoses.
Check it out. Don't assume.
I have read about an oem hose failure on a motorcycle. It was around ~2004 and a '84 owner on the old Yahoo list had a split on the AD hose next to the crimp collar. He reported he was riding when he squeezed the front brake lever and the lever came back to the handlebar. Along with the surprise, he mentioned that, when he pumped the lever, the spray of DOT 3 fluid went everywhere and ruined his paint and windscreen.
Yes, cars have a great safety record. Vehicles made after 1957 (in the USA) are required to have a redundant brake system with 2 master cylinders each pressurizing alternate front and back wheels. Loose line pressure in one system and at least you have a separate system controlling 2 wheels you can rely on.
My point: Loss of brake line pressure on motorcycles can be worse than on cars. On motorcycles, loose line pressure on your front brakes, a system that handles 80% of the braking load, you had better hope you have the room to use your back brake.
Finally, on my signature line I state: "Replace your oem rubber brake lines (because) They are long over due. Do it now."
I don't say because you will die if you don't. I let the reader's imagination conjure that up.
Perhaps I should say: Replace your oem rubber brake lines because your brakes will work better. On that, you and I agree.
Quote from: Pat Conlon on January 19, 2017, 11:18:09 AM
I'll base my conclusions on empirical evidence over anecdotal evidence any day.
So do I. Empirical evidence is exactly what the mechanic in the field sees. To suggest their observations are anecdotal is being dismissive of the experience and skills of an entire industry.
em·pir·i·cal əmˈpirik(ə)l
adjective
adjective empirical
based on, concerned with, or verifiable by observation or experience rather than theory or pure logic.
experiential practical heuristic firsthand hands-on observed evidence-based seen demonstrableI would be very surprised if hose manufacturers conducted any tests beyond mechanically simulated use (I have seen such a jig in operation first hand at Ford Product Engineering) and the known properties of the materials they use. Gathering empirical evidence would require putting it into service in large numbers and observing it's performance until such time as it fails.
I have no interest in keeping this thread alive nor addressing any other point you made but I do take exception to the above. Other than the average mileage of vehicles in the US I have not researched or read anything on the subject for the purpose of this discussion. If you have information or a link on how they are tested I would be interested to read it.
Re the old Volvo hose, maybe I should have balanced that out with the fact that I have also seen them fail while still under new car warranty!
I don't know whether they are your words or someone else's, but in my opinion, one is wrong and the other offensive. You know we have a member who is an authority on the word "empirical," perhaps he could settle it. :biggrin: Hmmm....maybe not.
You are a lucky man to have found a pristine '92. I don't know about over there but here, when I turn up to look at a "pristine" "as new" "showroom condition" etc bike and I'm confronted by some rough old shitbox (the camera
does lie), the answer when nailed about the gaping discrepancy between the ad and the bike is always the same, ....."for it's age"
I had never seen another one since I bought mine, until recently. I offered to buy it instantly at his asking price, which was very reasonable, and he withdrew it from sale. Not sure what was going on but I suspect the moment he realised it was actually about to go, he couldn't do it. If I ever find another one I will buy it in a heartbeat.
How about some photos.
Noel
I'll post some pictures as soon as I get those new Spiegler lines on......