redelk
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posted November 08, 2004 08:02 PM
 Edited By: redelk on 12 Nov 2004 17:29
Interesting data on Brake Fluid ....
I just got finished ordering some more brake fluid for our race team. They are really sold on this one brand and now refuse to use any other. Its kinda pricey when compared to my old favorite Motul RBF600, but after doing a little research, I think I figured out why. Below is a chart comparing Dry vs. Wet Boiling Points.
DOT 3 Standards - 401F / 284F
DOT 4 Standards - 446F / 311F
DOT 5 Standards - 500F / 356F
When it comes to the highest boiling points, Wildwood seems to be one of the leaders.
Wildwood EXP 600 - 626F / 417F
GS 610 - 610F / 421F
Brembo LCF600 - 601F / 399F
Motul RBF600 - 593F / 420F
Castrol SRF - 590F / 518F
AP Super 600 - 590F / 410F
Ferodo Racing (DOT 4) - 572F / NA (couldnt find data)
When looking at bang for the buck it seems that my favorite, Motul RBF600 is the clear winner (your price may vary).
Motul RBF600 - $12.95 / 500cc - $0.0259 per cc
AP Super 600 - $16.95 / 500cc - $0.0339
Ferodo Racing (DOT 4) - $22.95 / 500cc - $0.0459
Wildwood EXP 600 - $18.75 / 355cc - $0.0528
Castrol SRF - $64.50 / 1000cc - $0.0645
Brembo LCF600 - $64.50 / 1000cc - $0.0645
GS 610 - $39.95 / 473cc - $0.0845
So, whats the big deal? All of them have to have a similar boiling point, right? Sure, when your talking about the Dry boiling point. For the most part, all of them are even pretty close in their Wet boiling points as well. All except one, that is. There is where the difference is not only obvious, but why the team demands one brand over all others. Castrol SRF. Still, is SRF really worth TWO and a HALF TIMES the cost of Motul? As far as the riders on the team are concerned, yes. It is understandable that brake fluid would be an issue for a eight hour endurance race where one would be repeatedly slowing down from 150+ MPH speeds, lap after lap, but is it worth getting for normal street use? After all, there is no way one would even come close to heating up the brake fluid like an endurance racer. IMHO... yes.
The aspect of a race bike heating up the fluid might be true, but it boils down (pun intended) to the absorbing of moisture. Though a race bike will have to deal with moisture by the heating up of the brake fluid, is not because the fluid is breaking down and releasing moisture. Remember, brake systems absorb moisture. They dont create it. From what I have read, moisture can get into the brake system by numerous methods. Even through the rubber of your brake lines. You might have stainless steel braided lines, but what are these little braided lines wrapped around? All braided lines do is all but eliminate the expansion of the brake line itself. Hardly a barrier from moisture. Not to mention those rubber seals in the calipers, master cylinder and even the reservoir cap itself.
So, for the average street rider, heating up the fluid is not really as much of an issue as it is for a racer and moisture isnt that big of a deal, right? That is to a degree (another pun). Time is the enemy of the street rider. We will change out the brake fluid on the race bikes many times over the course of one season, but how often does the average street rider change his brake fluid? Once a year? Only when they buy new lines? Just adding some fluid while bleeding the lines does not count. Im talking about completely flushing out the lines then adding new fluid.
It only takes a couple of months before the boiling point of your fluid is a lot closer to the Wet than it is to the Dry. The fluid will be constantly getting moisture in it from the time you pour it in. How much may vary, but the end results are the same. If the brake fluid has a lower wet boiling point, the absorbed moisture will become an issue a lot faster then with a fluid that has a higher wet boiling point. This might not become apparent when cruising to the local Sonic, but it would be something you would not want to become aware of during a spirited ride on some back highway or in the shut down area of your local dragstrip.
If your brake fluid is been in your system for a while, then it is a given that it will have moisture in it. If you had the choice, which would you feel more comfortable with in your reservoir? Some DOT 4 fluid you bought at Wal-Mart that starts overheating at around 300F or would you prefer the extra buffer that an additional 200+F gives you as you are approaching that apex thats posted at 20 MPH (and your definitely over cooking it)? Ah, but there is a couple of downsides. Castrol SRF only comes in one liter cans and at over $60 a can. The other is that they HIGHLY RECOMMEND that you completely drain the system before putting in the SRF. Im guessing its mostly due to any of the remaining old fluid reducing the performance and of course, so youll use more SRF. Still, its always best to flush than it is to simply refill. Doesnt matter if your changing brands or not.
The upside is that because of its packaging. SRF comes in a metal can with two tops vs. a plastic bottle (which is actually absorbing moisture while sitting on the store shelf). The metal can will absorb far less moisture while sitting on your garage shelf. Even better yet, after you talk about the difference (and you will, I promise), all your riding buddies will be wanting some (of yours, of course). So wether you sell it or give it away, odds are that it wont be sitting on your shelf for the next two years. Our first can lasted about five months.
I now run SRF in my 10R and for those that have ridden with me, they can tell you that Im not hard on brakes. Mostly due to the fact that I ride like a wuss. On the other hand, they will also tell you that I do the distance. If I aint gonna be doing 250+ miles during the day's ride, I wont bother hitting the starter button. Even being a wuss, 250 miles of back highways does not only give my shift foot exercise, it also works out my right hand as well. Because ever time I roll it on, eventually Im gonna be grabbing a handful of lever. The 10Rs brakes are great to start with (especially after removing those damn metal plates behind the pads and putting braided lines on) , but knowing that every time (and I do mean EVERY TIME!) I grab that lever and I am almost startled over its grip... well, its just the way I like it. Reliable and constant. From the first time I pull on that lever to the last time when I pull back into my garage.
I will have to admit, on VERY RARE occasions, there were times I thought my pads were going out or at least getting glazed. Scuffing my pads and wiping the rotors became a ritual in my garage and only with little success. So did getting out the MightVac and bleeding the lines. After switching to SRF, it seems like those rituals are all but forgotten. Sure, Ill do em every once and a while, but that's only because I am bored and at that time I couldnt afford any of those high dollar aftermarket goodies that I could be putting on instead.
Now if I could just get Castrol to send me a free case for this shameless plug, Id be happy. Yeah, I know... wishful thinking. Still, after reading how so many folks have spent big bucks to make sure they have the very best of pads, lines and even rotors, it amazes me that when it comes to the most important part of the system, the part that makes all those high dollar components work... they settle for something that is just good. When a complete set of Perfomance Friction (or like brand)front pads for my 10R cost more than a liter of SRF, it just really doesn't make sense to skimp out on the fluid. If a wuss rider like me can REALLY tell the difference, imaging what you serious riders will be able to tell. Youll be surprised. No matter which category you might fall into.
One last note... DOT 5 fluid is basically worthless. The silicone in DOT 5 is slightly more compressible than glycol fluid. It has a higher wet boiling point because it DOES NOT absorb moisture. Silicone fluids are NOT hydroscopic, meaning that they will not absorb moisture. This is DOT 5s downfall. As the brake system produces moisture, a conventional brake fluid will absorb it but a silicone fluid WILL NOT. The moisture is still in the system but instead of absorbing (mixing) into the brake fluid (admittedly reducing its boiling point), it just sits there in little water pockets waiting for the brake system to get hot so that it can vaporize. Even a well soaked brake fluid will have a higher boiling point than water and even water has a higher viscosity that AIR! Of course, its also not recommended for use in most bikes anyway.
Naturally, this is just my opinion and of course, I could care less what you think. 
____________
There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games.
-Ernest Hemingway
   
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bovinespongiformencephalo
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posted November 08, 2004 10:37 PM
quote:
...is it worth getting for "normal street use"? After all, there is no way one would even come close to "heating up" the brake fluid like an endurance racer.
No way? Really. Come visit Palomar sometime.
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12RPilot
Pro
Posts: 1094
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posted November 09, 2004 02:29 AM
Edited By: 12RPilot on 9 Nov 2004 02:30
I'd have to see some evidence of water molecules migrating through plastic as if it were porous. I have alot of experience that counters that assertion. But if I were a marketing guy for the brake fluid companies, I'd spread a rumor that customers need to buy more brake fluid periodically because water may contaminate anything stored in a container, even if sealed. However, like Sherm, I am only offering my opinion here.
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slug
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Out in search of my mind...
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posted November 09, 2004 03:11 AM
+1 on the DOT-5 being useless....
brake fluid NEEDS to be hygroscopic
though i usually use the "walmart" variety of the castrol fluid ;P
and guilty of only changing once a year heh
and my poor truck...sheesh it eats brake fluid...brand new fresh clean fluid, and flushed clean all the way around
and within a week it was already changing colours... 
 
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Michael Lee
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posted November 09, 2004 04:08 AM
Just a wealth of information
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Marcos Peguero
Zone Head
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posted November 09, 2004 04:17 AM
I use motorex 5.1 dry 509F and the results are very impresive.
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fish_antlers
Administrator
The Truth is Out There
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posted November 09, 2004 09:07 AM
(now on the frontpage)
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What business is it of yours where I'm from, Friendo?
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frEEk
Administrator
ummm... yeah
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posted November 09, 2004 10:01 AM
quote:
and guilty of only changing once a year heh
i'm supposed to change the brake build? chyaa! next ur gonna tell me i should lube all the cables, check nuts & bolts, change the coolant and even wash the bike! sheesh!
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k bryant
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posted November 09, 2004 10:02 AM
My, my Pastor - aren't we the research analyist.... Nicely done.
I mostly use Motul or Castrol. No abnormal issues on the track, but I used to change it every race. For track days, no issues at all. Simply don't ride that hard anymore..... Sure, I've over-heated them and lost feel, mostly on the rear (Dirt Track thing from dragging it to much...), and at times the front's gone spongy, but no night and day differences. Proper maintance is the key. Flush often. It's the cheapest insurance...
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VincentHill
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posted November 09, 2004 12:09 PM
Personally I use ATE Super Blue a German Brake Fluid that is Dot 4+ rated and is above Dot 5 standards. Dry is 536 and wet is 392 and cost $18.84 list and my cost is $13.98 per 1,000 CC
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jonwright
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posted November 09, 2004 12:50 PM
Edited By: jonwright on 9 Nov 2004 12:58
The Master of Minutia has struck again! Stuff like this is why having Sherm on the team is such a good deal.
They use SRF for Formula 1 cars - that's all I need to know. And when the brake lever is firmer after putting in SRF ... that's all my finger needs to know.
I just ride 'em.
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Marcos Peguero
Zone Head
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posted November 10, 2004 04:30 AM
http://www.hrpworld.com/index.cfm?form_cat_id=92&action=category
go to the GS610 they have there a comparison chart.
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salsa1
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posted November 10, 2004 06:16 AM
Edited By: salsa1 on 10 Nov 2004 12:22
I am using synthetic brake fluid (off the shelf advance auto parts store); claims compatibility with factory and other DOT standards.
Isn't every fluid that is synthetic have improved properties over conventional fluids (smile)hehe?
I hope so cause thats what I put in.....good nuf' for street I believe..
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Salsa1
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slug
Pro
Out in search of my mind...
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posted November 10, 2004 06:37 PM
the problem with the synthetic is that (the stuff i have seen anyway) is not hygroscopic, and therefore does not absorb moisture...
as such it becomes a liability in a system where moisture is introduced.
Except for its low boiling point, water is an excellent hydrualic fluid. unfortunately it tends to leak more readily and has this nasty habit of boiling when it gets hot...
if the brake fluid does not absorb the moisture, it pools at low point (oil floats on water) and that low point typically is the highest heat part of the system.
water then boils, vapor which is VERY compressible fills the calipers/lines and voila, mushy useless brakes....
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pdb1964
Zone Head
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posted November 10, 2004 07:35 PM
and when water turns to vapor, it expands, pushing out on your brake pads. Now your pads are dragging, or may even worse, the brakes apply without your input.
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fish_antlers
Administrator
The Truth is Out There
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posted November 10, 2004 07:39 PM
the brake system is sealed... how will it get from inside the hydraulic lines and the sealed system and into your pads? unlikely...
just thinking about what you said.
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What business is it of yours where I'm from, Friendo?
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bovinespongiformencephalo
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posted November 10, 2004 08:18 PM
You need more caffeine fish_breath. That or give up on the thinking 
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k bryant
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posted November 11, 2004 10:01 AM
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Y2KZX12R
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posted November 12, 2004 01:59 PM
Interesting. Thanks Red.
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Y2KZX12R
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iculukn
Expert Class
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posted November 12, 2004 05:13 PM
Redelk - tell me again what magazine you write for? Dang boy, if we could get you doing a monthly article like the above, I could stop spending on all the magazines and just follow your input  Nicely wrote, seriously
"Fish Breath", now dat funny...Hummm, sorry bout that fish
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redelk
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Please... speak to the hand.
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posted November 12, 2004 05:28 PM
Quite a while back, my dealer bought a case and paid over $90 a can. The Parts Mgr. thought it was $90 a CASE! Imagine thier surprise when the got the invoice. Need less to say, cans of SRF haven't been flying off their shelves. In other words, they haven't sold a single can.
After several months, they had given away two cans. I got one of those cans for doing some work on the one of the parts guy's bike on the side. After several attempts by their Service Dept. to fix his Bandit 400, I told him I'd do it for free. I considered it to be a challange. Well, I got it running and he gave me a can for my troubles (though it was pretty easy to install a new rectifier and clean the carbs). That's how the team got turned on to SRF.
Well, I just found out today that they are tired of looking at those high dollar cans on their shelves and just want to get rid of them. Jonathan picked up a can for $30. What kinda sucks is that I just ordered a can for the team and paided $71 including shipping. All the same, I'm going down there tomorrow and buying two more cans at $30 each. The team can pay for one and I'll pay for the other.
Why in the world would we need FOUR LITERS of brake fluid? Especially that "high dollar" stuff? Simple, really. Because it is kinda pricey (Even discounted to about the same price as Motul - per cc), I've been kinda reluctant to TRULY FLUSH the brake systems of both my bikes and the team's bikes. Yeah, I'd run enough fluid through until it was "clean", but never really flush the whole system. The point is, if you don't COMPLETELY FLUSH out the whole system, it's really not much better than just adding fluid. You might be getting out most of the moisture and debris out, but not all of it. Kinda defeats the whole purpose of running such fluid in the first place.
Soooooo, a good thing to remember is that if your going to change your fluid, don't skimp out and just run enough fluid through to "clean it out". If you want to do it right, Drain out the old fluid. Flush the system out with new fluid. Then refill the system with some more new fluid and bleed accordingly. It doesn't matter if you are using SRF or Wal-Mart brake fluid. Sure it's a hassle, but would you reuse your oil after running it through a few paper towels? If changing your oil is thought to be so important, flushing your brake system before changing the fluid would be even more important. All bikes can "go". It's that "stop" that really counts.
____________
There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games.
-Ernest Hemingway
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CRoberts
Parking Attendant
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posted November 15, 2004 09:23 PM
note to self !!! SRF
I will be running on down tomarrow to see dave. I will be aquiring a can for the stash. I will also give Cal your number, so you two can spaek about my new favorite bike.
Sherm, that ZX-10 is everything my 636 wants to be. I think i will have to settle for a new 636. Time to spend some money with Marcus for the endurance bike.
I need to barrow your runout guage for the left rotor, looks like 1.5 mill warp on the left rotor, plus the fluid is toasted from Sunday 123, 7, 16 ride, also need you ideas on changing the from valves and springs on the front forks.
Sincerely,
CRoberts
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jonwright
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posted November 16, 2004 07:33 AM
Damn, Chris. You hijack like a motherfucker.
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swft
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Full throttle!
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posted November 16, 2004 10:46 AM
Hey, I need to refresh your MotoGP stuff.
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