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Brakes Revisited

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2012YellowBoss said:
Anyone know what the difference is between the Motul RBF 600 and 660? Looks to me like it is the same fluid but the 600 has nitrogen filled bottles from the factory.
60? :)

Is that the boiling point?
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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More info, but I don't have RBF660 listed - see boiling points. I you want better than RBF600 I'd suggest Pagid or Castrol. I don't carry RBF660 because I had some issues with it drawing too much moisture in the past. The Castrol SRF is some excellent fluid and has special additives to make it a lot less hygroscopic than other fluids in the temp boiling range, but it's not cheap.

http://www.trackdaysolutions.com/boss302.html
 

PeteInCT

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ArizonaGT said:
SRF is 80 bucks a bottle lol

If you flush once or twice a season the water absorption won't matter even with a less astronomically priced fluid

Its a liter vs 500ml and the point is you don't have to flush 3 times a season do it ends up to be cheaper in the long run. Plus it had much higher boiling points. I use it and it costs me almost what I sell it for, no one gets rich off of selling brake fluid ;D I agree its not for everyone.
 
I was wondering if anyone here had inside info. I suspect that they may be the same fluid but packaged differently because they both say 100% Synthetic and the 600 says "filled with Nitrogen, increasing shelf life and eliminating contamination while factory sealed" The RBF600 seems to be the choise of most trackers. I will drop them an email and see what they say.

I have heard the same about the 660 absorbing water but never saw any hard data, in other words someone having it analized to show the water content. I personnally don't know how to tell if one fluid has absorbed more water then another? I can tell in a street car the fluid is old and has mosture because of the color but I am clueless as to the percent of mosture.

Below is directly off Motul's site however the 600 on the bottle itself says "minimun wet boiling point 383 and typical wet boiling point is 421". I remember reading somewhere that 3 1/2 percent water is max contamination. One thing I have learned from speaking with experts at the races is always look at the wet boiling point, once you crack the bottle open it is no longer dry. I tend to add a few degrees to wet since I change out the fluid completely for each track day. If it is two days in a row or another track day within a couple of weeks I will only flush the calipers, in any case the fluid is never more then one month old.

RBF 660 Factory Line

Very high dry boiling point of 617F (325C) and a wet boiling point of 400F (204C). For all types of hydraulic brake and clutch actuators requiring non-silicone synthetic fluid. Specially designed to resist extreme temperature generated by racing brakes (carbon and ceramic) only allowing a minimal air entrance for brake cooling.

600
Extreme high performance polyglycol brake fluid. Far exceeds the standards of DOT 4. Each bottle is filled with Nitrogen, increasing shelf life and eliminating contamination while factory sealed. Extremely high dry boiling point 594F(312C) helps prevent vapor lock and brake fade during hard use, with excellent recovery time. Wet boiling point 401F(205C)

The Castrol is good stuff and you see race teams using it, still it is twice the price of the Motul (like Pete said it is sold in containers twice the size of the Motul). Problem is I would do the same and change before each track event, that can get costly but not as costly as losing the brakes I guess.
 

PeteInCT

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I'm not so sure that just cracking the bottle means that the wet boiling point is the true boiling point of the fluid. This from a wiki page: "Quality standards refer to a brake fluid's "dry" and "wet" boiling points. Wet boiling point, which is usually much lower (although above most normal service temperatures), refers to the fluid's boiling point after absorbing a certain amount of moisture. This is several (single digit) percent, varying from formulation to formulation." I guess the question is what is the curve that maps a particular fluids actual boiling point vs. % of water content. It would be interesting to see this curve for various fluids. I'm going to guess that many race teams use SRF because it has properties that make it less hygroscopic than it would be otherwise. Implication being that in a real world scenario it's boiling point would remain higher for a longer period of time (?)
 
I have a tendency to stick with what works. I have boiled Brembo LCF600 but have never boiled Super Blue or Amber Typ200. That said I'm bleeding before most events to keep some fresh fluid coming in on a regular basis. I hot this same advice from one of the pro racers at Track Attack. It's a pretty reasonably priced fluid and I'm not exactly easy on brakes..
 
PeteInCT said:
I'm not so sure that just cracking the bottle means that the wet boiling point is the true boiling point of the fluid.
No, I don't think opening a can automatically makes it the lowest wet boiling point but it is not at the highest dry boiling point anymore. It was Mike from Carbotech that told me this, it is something I always knew and that just backed up what I believed. He did not say that opening the can goes to lowest boiling point just that I need to look at the wet number more then the dry number when choosing fluid. When bleeding I always put the caps back on in between top offs and I do not use fluid that has been opened for more then one month for the track.

cloud9 said:
I have a tendency to stick with what works. I have boiled Brembo LCF600 but have never boiled Super Blue or Amber Typ200. That said I'm bleeding before most events to keep some fresh fluid coming in on a regular basis. I hot this same advice from one of the pro racers at Track Attack. It's a pretty reasonably priced fluid and I'm not exactly easy on brakes..

I have been using the Super Blue since I started, clean fluid every track day. I have boiled them twice and had the pedal go soft on another day. Last time out the caliper was leaking and it had to be replaced so I am not sure I can blame the fluid or not, or maybe the heat/boiling caused the leak? Anyway I thought it was time to step up to the Motul, going to start with 600 and see how that holds up. Considering how many parts we have had replaced at almost the same time, you better keep an eye on the front calipers this year.
 

Sesshomurai

Im going with this kit.

http://store.kennybrown.com/product/brake-kits/baer-extreme-6r-front-brake-system-2005-2014-mustang-boss-302-and-gt500

Will add the 6p rears down the road.
 

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