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Dot 5.1 is very rare, a motorcycle shop *might* have it, but even there it is very rare to see it.

Dot 4 and dot 3 are compatable with dot 5.1. You DO NOT want dot 5 though.

You usually have to order dot 5.1 from hope. Dot 4 is the best replacement, although there are very good dot 3 fluids out there that exceed the baseline dot 4 specifications.
 

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Jm. said:
Dot 5.1 is very rare, a motorcycle shop *might* have it, but even there it is very rare to see it.

Dot 4 and dot 3 are compatable with dot 5.1. You DO NOT want dot 5 though.

You usually have to order dot 5.1 from hope. Dot 4 is the best replacement, although there are very good dot 3 fluids out there that exceed the baseline dot 4 specifications.
are you sure???????? cuz i don't want to screw everything up...
 

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oh yes, I'm sure. I've been buying dot fluid and bleeding brakes since 1999. Hayes brakes can take dot 3 or 4. Hope brakes use dot 5.1 and dot 4. Dot 3 is chemically similer to dot 4, in the sense that it won't harm the seals or anything on your bike, it simply has a lower boiling temperature so it's not quite as resistant to temperature differences, but there ARE a lot of dot 3 fluids that far exceed the baseline specifications of dot 3 fluid, so you can put dot 3 in a brake that uses dot 4 or dot 5.1 and it will be fine.

Dot 5.1 is good because it doesn't absorb much water and it can work at very high temperatures without expanding, Dot 3 and 4 are not quite as good at this, but they are still well within the "ok" range in my experience.

To be on the safe side, just get dot 4.
 

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thebikedoctor33 said:
are you sure???????? cuz i don't want to screw everything up...
yes, he's correct. The main difference between DOT 3, 4 and 5.1 is the boiling point (higher number equals higher boiling point), but 5.1 shouldn't be necessary, and the only possible consequence is performance, but i highly doubt the Hopes reach temperatures high enough to truly warrant it.
 

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but buy the smallest/cheapest bottle you can, because you'll be throwing it away after you bleed the brakes.

you'll be throwing it away because if you leave a half-open bottle of brake fluid around (even if the top is on tight) it will absorb water from the atmosphere, and result in poor performance when you bleed the brakes 6 months or whatever down the road...
 

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when they absorb moisture will that make them feel more spongy when you bleed them. cause i got my brakes blead like 4 weeks ago at my bike shop and they are good but still a little spongy. you think it could be the bottle of fluid they used had been sitting there for a while. havent really felt my brake lever in a week or so so i forget if they are kinda bad or not but i felt someone elses hayes mags and they were just like totally solid. no sponginess at all. thats how i want mine to feel.
 

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dhracer1067 said:
when they absorb moisture will that make them feel more spongy when you bleed them. cause i got my brakes blead like 4 weeks ago at my bike shop and they are good but still a little spongy. you think it could be the bottle of fluid they used had been sitting there for a while. havent really felt my brake lever in a week or so so i forget if they are kinda bad or not but i felt someone elses hayes mags and they were just like totally solid. no sponginess at all. thats how i want mine to feel.
most likely they did not bleed it properly and there is air still trapped in the lines. It most likely needs to be bled; i'd go back there and ask them to touch it up gratis.
 

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Dot 5

I don't believe the myth about DOT 5

I've been using it for more than 10 years in my '77 RD400...

DOT 5 is silicone and is non-corrosive and doesn't absorb moisture like the DOT 3/4/5.1

I use mechanical disc brakes (3 Avid & 2 Shimano), nice and simple
 

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zedro said:
most likely they did not bleed it properly and there is air still trapped in the lines. It most likely needs to be bled; i'd go back there and ask them to touch it up gratis.
well i mean is fine. it doesnt matter at all to me. but the other ones i fell were just like rock solid with the perfect amount of pull and everything. its too much trouble anyways. id just bleed them myself but i dont have any fluid. well atleast new fluid. only crap i have is like a year old. too bad mechanical discbrakes arent very good. im too lazy to be messin with fluid and bleeding and all that stuff involved with getting hydros workin right. i can set my pistons back in and change pads and move my lever around but i dont really care to do anymore then that.
 

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dhracer1067 said:
well i mean is fine. it doesnt matter at all to me. but the other ones i fell were just like rock solid with the perfect amount of pull and everything. its too much trouble anyways. id just bleed them myself but i dont have any fluid. well atleast new fluid. only crap i have is like a year old. too bad mechanical discbrakes arent very good. im too lazy to be messin with fluid and bleeding and all that stuff involved with getting hydros workin right. i can set my pistons back in and change pads and move my lever around but i dont really care to do anymore then that.
well, when they're bled right, they can hold upto two years. Its just a matter of getting right.
 

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oh yeah. one thing. i noticed today when i finally washed my bike after getting back from sugar 2 weeks ago or so some fluid was around the bleed valve on the caliper. do i need to like tighten it a bit more or something.


does anyone wanna give me like 50 bucks so i can afford race registration in september for the maxxis series finals at windrock. pwease. i accept pay pal. or you can buy a huckmeisters shirt.
 
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