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Discussion Starter · #1 ·
I upgrade front & rear brake lines with Venhill lines and i have Gulf Racing Brake Fluid Dot 5.1 to replace Dot 4, anywone have use them and can give me feedback, stock lines arent very mushy and according to Gulf, it seem that Dot 5.1 can improve them?
 

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I have not installed my Venhill lines yet, but I do have Motul 5.1. I think the fluid can improve braking in extreme circumstances, but little. The lines will be a great improvement.

I nearly purchased the RBF600 fluid, but it looks like it is not as stable as 5.1, and absorbs water faster. Good for racing, not so good for real riding.
 

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5.1 has a higher dry boiling point.... Won't make bit of difference to you.
 

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5.1 is glycol/ether based so is still hydrosopic (absorbs moisture) so I would suggest 5.0 which is silicon based and is not hydrosopic and has the same specs.
You need to question your requirement though, yes the boiling point and viscosity limit are higher but do you need that. If yes I'd personally still go with non hydrosopic.
 

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5.1 is glycol/ether based so is still hydrosopic (absorbs moisture) so I would suggest 5.0 which is silicon based and is not hydrosopic and has the same specs.
You need to question your requirement though, yes the boiling point and viscosity limit are higher but do you need that. If yes I'd personally still go with non hydrosopic.
erm

DOT 3,4,5.1 is interchangable.

DOT 5 will just ruin the brake lines yo.
 

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Great article on DOT 3/4 and 5 not being compatible.
Brake fluids, DOT 4 and DOT 5 (silicone), V8 Register, MG Car Club

In reference to DOT 5 silicone-based fluid:
"It must be pointed out that the non hygroscopic nature of silicone can also be a disadvantage. For example, if any water does enter the braking system it will gravitate to the lowest point rather than being absorbed in a distributed way. If this is in a brake pipe the water may cause local corrosion: it will be there a long time as the reason for using silicone is that it doesn't need changing. Perhaps worse, it may freeze . . . . the consequences of a frozen section in a brake pipe could be very interesting . . . and difficult to diagnose when later examined in a warm workshop."
 

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You can store a bike indoors, never wash it or ride in the rain and the hygroscopc nature of DOT 3/4/5.1 will still pull water out of the air. These photos are of fluid from a new, 2012 Yamaha that was bought in Nov. 2013. It'd never been outside until a few days before these were taken. That dark color is from water absorbed by the brake fluid.
Imagine all that deposited down in the calipers instead if it'd had DOT 5.
Yikes!

Street bike?
I recommend plain old DOT 4, changing it every other year on your birthday and it'll be just fine.
:D
Font Auto part Glass Metal
 
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We tried 5.0 and 5.1 when we raced motocross with poor results. Had to change it out frequently. Not worth the hassle. My brakes are monster with Dot 4, braided lines, and EBC HH pads. I am not doing track days, but my spirited rides see very little fade.
 

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erm

DOT 3,4,5.1 is interchangable.

DOT 5 will just ruin the brake lines yo.
Yes and No, I disagree slightly.
Yes you are right 3,4 and 5.1 are all gycol based and can be swapped easily.
No DOT5 doesn't ruin lines IF you know the limitations and use (can't be mixed etc) see link by edgyver.
Hence my warning on if you NEED IT and understand what you are doing...
Most don't and then wonder why things go wrong, the forums can be great for ideas but you need to be wary.
Everything is "fit for purpose", it is only when you use it for something it wasn't designed for that you run into trouble.Yo
 

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Discussion Starter · #11 ·
From what i read, DOT 5.1 was thinner and give a better feedback, the reason it was used on abs brakes system to help the abs pump to react quickly and if you use them on no abs systems, the feel will be better.
 

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Yes and No, I disagree slightly.
Yes you are right 3,4 and 5.1 are all gycol based and can be swapped easily.
No DOT5 doesn't ruin lines IF you know the limitations and use (can't be mixed etc) see link by edgyver.
Hence my warning on if you NEED IT and understand what you are doing...
Most don't and then wonder why things go wrong, the forums can be great for ideas but you need to be wary.
Everything is "fit for purpose", it is only when you use it for something it wasn't designed for that you run into trouble.Yo
you dont read instructions on the brake fluid fill cap do you?

not my problem ... not my bike...
 

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you dont read instructions on the brake fluid fill cap do you?

not my problem ... not my bike...
1. What if DOT4 is phased out and replaced, would you stop riding because you couldn't get it anymore. Or would you wait for Yamaha to release a new cap?:confused:



2. Yes/No/erm/no idea, must be an answer to that one somewhere, just not here.....


The human brain starts working the moment you are born and never stops until you stand up to speak in public.
George Jessel
 

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1. What if DOT4 is phased out and replaced, would you stop riding because you couldn't get it anymore. Or would you wait for Yamaha to release a new cap?:confused:



2. Yes/No/erm/no idea, must be an answer to that one somewhere, just not here.....


The human brain starts working the moment you are born and never stops until you stand up to speak in public.
George Jessel
maybe in auckland , not in my place (man, the place u live must suck to phase out dot 4)
 

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Dot 5 is for use in non abs systems, dot 5.1, synthetic, can be used in anything. The higher ratings are solely boiling point. When fluid boils it makes air in the line and causes inconsistent brake force
 

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Discussion Starter · #16 ·
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