Brake Fluid

[Billy Smart]

Dot 4.1, 5.1, 6.1 what is the difference? is it just a temperature rating thing? also when would these ratings be used, i.e everyday driving, tracking racing ect..

Thanks

Billy

[obehave]

Dot 5.1 is recommended for ABS brake systems.

Dot 4 is performance oriented and usually has the best wet and dry temp ratings for natural fluids.

Dot 5 is silicone based, has good temp ratings and is not agroscopic like conventional fluids. This is a good thing. It is not com[atible with conventional fluids though.

For further info venture to your local internet search engine

[ChallengeRacer]

Quote: Originally Posted by Billy Smart

Dot 4.1, 5.1, 6.1 what is the difference? is it just a temperature rating thing? also when would these ratings be used, i.e everyday driving, tracking racing ect..

Thanks

Billy

Billy,

In our racing, and in hot climates, the Mini's brakes are just not up to the task. We have switched to steel braided hoses, changed pad compounds, and have fabricated brake ducts to get air to the calipers. Guiding us in this was the use of temperature paint (it changes color when certain temperatures are exceeded).

Anyway, the engineering work pointed us to a brake fluid with a higher dry temperature boiling point and we settled on AP600, which is what Formula I teams use. Castrol SRF is a synthetic and is probably the best, but it's just too expensive.

Since changing to the AP600 we have not had any problems with boiling the fluid, and I use it on the street as well. Of course, we change the fluid after every race anyway, which is another reason the SRF is not economically viable.

For the street, I cannot see how you will ever use the brakes hard enough to boil the fluid. Much more important is simply changing it out every year or so, and with the AP600, you really cannot go wrong.

Hope this helps!

Stephen.