What is good brake fluid?
- Thread starter KBacon
- Start date
moto_mx131
New Member
I used the Motul RBF600 for the first time at RD ATL couple weeks ago it worked great.
HondaGalToo
Control Rider
Another fan of the Motul RBF. It's also a DOT 4, but has a higher boiling point than other DOT4s, which means better track performance.
Whatever you do, don't let anyone tell you to use DOT 5. DOT 5.1 is ok, but DOT 5 is incompatible with systems designed for DOT3/4.
Whatever you do, don't let anyone tell you to use DOT 5. DOT 5.1 is ok, but DOT 5 is incompatible with systems designed for DOT3/4.
Trent1098S
New Member
Motul.
DOT5 will RUIN Brembo systems (and probably others). Some poor bugger on the Ducati boards roached a Brembo master, clutch master, and clutch slave with DOT5 last year.
DOT5 will RUIN Brembo systems (and probably others). Some poor bugger on the Ducati boards roached a Brembo master, clutch master, and clutch slave with DOT5 last year.
geekmug
New Member
Fluids are like religion, some people worship the almighty Motul and others the divine Amsoil. For what it's worth, replacing your brake fluid with any DOT4 or DOT5.1 fluid that is fresh from a sealed bottle every year will be good enough for a large majority of track day riders.
I'd be interested to hear anyone relate a story of having experienced vapor lock with generic (but fresh!) DOT4 fluid in a motorcycle brake system. A story about car doesn't count because it's not the same, a car is generating *way* more heat in the brake system -- consider that track cars run the same speeds but often weigh 5x or 6x as much and the brake rotors are most often recessed into wheel wells with limited airflow, and they use the same exact fluids.
Needless to say, I'm quite skeptical that your money is well spent buying the $20 bottle versus the $4 bottle. I know I will get replies that "it's $16 worth of peace of mind" but we are really talking about brake fade and not a catastrophic failure. Take your $16 saved and go buy some drill bits and a hose clamp and safety wire your oil plug and filter; that's money better spent for peace of mind.
If money is no object, then you should buy some Castrol SRF because I know of no fluid with higher dry and wet boiling points.
ronhix
New Member
Hix Racing has used this stuff for the last few years in all our bikes and it is awesome.
I think you can get it from the www.Trackdaystore.com
I think you can get it from the www.Trackdaystore.com
some guy #2
Member
motul rbf600 but only because i got 4 bottles for the price of 2!
otherwise just changing the fluid is a good idea
otherwise just changing the fluid is a good idea
LUCKEDUCK
New Member
i just replaced the fluid at the beginning of the season with motorex dot 4 and ive had good luck and little to no fade with this.... you would be happy with pretty much any kind of "performance" fluid.. like its been said before change it every year with a new bottle and you will be good to go!!
Motofun352
Control Rider
I've been using Belray Dot 4 for years...no problems...not cheap at $7 a bottle but certainly not as expensive as the others mentioned. With quite a few bikes and fluid changes every year (even on the classics that don't get used much), the cost adds up fast.
Todd Stinson
New Member
My understanding is that the high performance fluids do in fact have higher boiling points but they absorb moisture fairly quickly negating that advantage if the fluid is not changed regularly. Changing the fluid often is the most important thing. Once a year may not be enough if you are looking to maintain optimum performance. I have always used the Valvoline syntec and just changed it 2-3 times per year, which you can afford to do at it's price.
Just in case you were wondering
Castrol SRF - dry boiling point 590 wet boiling 518
NEO Super DOT - dry boiling point 585 wet boiling 421
Motul Racing 600 - dry boiling point 585 wet boiling421
Motul DOT 5.1 - dry boiling point 509 wet boiling 365
ATE Type 200/ATE Super Blue - dry boiling point 536 wet boiling 392
Valvoline High Perf Synpower - dry boiling point 503 wet boiling 343
ATE SL - dry boiling point 500 wet boiling 329
Castrol LMA - dry boiling point 450 wet boiling 311
Gunk DOT 4 Brake Fluid - dry boiling point 510 wet boiling 311
DOT 5 Spec - dry boiling point 500 wet boiling 346
DOT 4 Spec - dry boiling point 446 wet boiling 311
DOT 3 Spec - dry boiling point 401 wet boiling 284
Castrol SRF - dry boiling point 590 wet boiling 518
NEO Super DOT - dry boiling point 585 wet boiling 421
Motul Racing 600 - dry boiling point 585 wet boiling421
Motul DOT 5.1 - dry boiling point 509 wet boiling 365
ATE Type 200/ATE Super Blue - dry boiling point 536 wet boiling 392
Valvoline High Perf Synpower - dry boiling point 503 wet boiling 343
ATE SL - dry boiling point 500 wet boiling 329
Castrol LMA - dry boiling point 450 wet boiling 311
Gunk DOT 4 Brake Fluid - dry boiling point 510 wet boiling 311
DOT 5 Spec - dry boiling point 500 wet boiling 346
DOT 4 Spec - dry boiling point 446 wet boiling 311
DOT 3 Spec - dry boiling point 401 wet boiling 284
I agree with the bulk of your post, but brake fade can be "catastrophic failure" when your brakes fade too bad to slow down for turn 1.
I switched to Castrol SRF for the race bike in 2008. It is very good fluid, but the majority of riders will not need the $60 brake fluid, so I left it off my first post.
geekmug
New Member
Generally speaking, DOT 5.1 > DOT 4 > DOT 3, with an appropriate set of prices to match. Brake fluid is designed to absorb water; there will always be moisture ingress in your brake system, and you do not want it pool and boil and become steam, so it is absorbed into the brake fluid. The chemistry of DOT 5.1 is basically the same as DOT 4, but you are stating with a better higher dry boiling point, so the boiling point for a given amount of moisture content is proportionally higher too.