Hope Disc Brake Fluid

[crispyboy]

Hello everyone i was just wondering if there is alot of difference between different brake fluid for Hope brakes ??

As in DOT 4 and Dot 5.1 is there a big difference in that ?

When i say difference i mean finger feel:

Spongy

Hard

[Alex Dark]

Fluid = incompressible.

Dot 4 is a revision of dot 5 ( or vice versa ) and is slightly improved in some areas. Both will be fine , and nearly definitely unnoticeable.

[Matt Burrows]

Dot 5 is not the same as Dot 5.1! Hope brakes use 4 or 5.1 like Ryan said. 5.1 is the higher grade, with higher boiling point which helps when coming down the side of a mountain. For trials it won't matter what you use between the two, it won't make any difference to lever feel

[Shaun H]

Dot 5 is not the same as Dot 5.1! Hope brakes use 4 or 5.1 like Ryan said. 5.1 is the higher grade, with higher boiling point which helps when coming down the side of a mountain. For trials it won't matter what you use between the two, it won't make any difference to lever feel

Unless they have different viscosity?

[Happydaze]

The viscosity is the same between the fluids, the difference being boiling point Dot 4 boils at 140ish degrees C. Dot 5 is the odd one out, its silicone based, what effect that would have I don't know, But I suspect seal failure would probably follow quite shortly after.

[sstein]

Go for dot 5.1, as already said it has a higher boiling point which means that if you do like to go down big hills with the brakes on then you are less likely to get brake fade, also it lasts longer before you need a re-bleed. Also contrary to what some one has said I am pretty sure that fluid does compress slightly, dot 4 a little more so than dot 5.1 though you are very unlikely to notice that! 

[Alex Dark]

Fluid is widely regarded as being incompressible due to it taking gigatons of force to reduce it's volume. Fairly sure anyway....

[Will Arnold]

might be worth looking into which absorbs moisture slower too. i know they both take on water like a bugger!