Brake Fluid

[Toast]

CaN, there was heaps about brake fluid in this post

Cheers Postie.

Post #33 there pretty much tells the whole story…I think I’ll be going for some 5.1 next time, which sounds a lot like the ‘Racing Dot 4’ that CaN mentioned in this thread.

[Kwaka14]

do you have an impact driver? that is always helpfull for removing such screws.

try (carefully) drilling the head out and then when you've taken the lid off use a pair of visegrips on the shaft, see if you can fit an easy out in the mashed up bit of thread first (most enginerring supplies places will have one), then replace the screw.

[Cajun]

i replaced the stock fluid in the 600 and 1000, with just standard EBC dot 4 and huge improvement all round.

[The Stranger:Me]

Cheers Postie.

Post #33 there pretty much tells the whole story…I think I’ll be going for some 5.1 next time, which sounds a lot like the ‘Racing Dot 4’ that CaN mentioned in this thread.

Except the 5.1 has a lower boiling point and according to Race Brakes will deteriorate quicker in severe (race) conditions.

Not that it probably matters to mere mortals.

[slimjim]

So they say brake fluid should be replaced every 12 months. I didn't know if this had been done in the last 12 months and the handle was getting a little more travel lately so I took the opportunity to replace the brake fluid.
But what with?
Well it needs to be dot 4. I know dot 5 has a higher boiling point, but is silicone based and I understand should not be used in a system not designed for dot 5.
So I went into repco and got a fresh bottle of dot 4 and use the vacuum bleeder to get rid of the old and replace the fluid.
All good, feel has returned to the lever.

But wait, there's more. Just sorting out my sons' boy racer and as it has had an engine transplant to a significantly more powerful engine I wanted to ensure the brakes were up to scratch. One thing recommended to us was racing fluid.

It goes like this (or so they say) dot 4 fluid should boil at no less than 230c, dot 5 at no less than 250c. Now we already know you shouldn't use dot 5 in a dot 4 system, but they have dot 4 race fluid which boils at over 300c. As well as that it is supposedly less compressible.

So I replaced the repco dot 4 fluid on the bike (only 2 weeks old now) with dot 4 race fluid. Well bugger me. the lever is now tight as a... well lets just say it is significantly tighter and has less travel and more feel to it.

So, maybe there is a difference between the cheap shit and the expensive stuff.

can i ask are you running braided lines to your brakes, as if your lever feels that firm you could quiet easly bust a standard brake hose, (splitting normal brake hose)while under quick pressure braking,?

[imdying]

can i ask are you running braided lines to your brakes, as if your lever feels that firm you could quiet easly bust a standard brake hose, (splitting normal brake hose)while under quick pressure braking,?

Not a chance.

/edit: In fact, a braided brake line is considerably more likely to suffer a mechanical failure than a regular hose.

[MacD]

another thing Col,
on mine it looks low, but that's just 'cos of the angle i've tilted the lever, for better riding/braking position. once you level it up, it might be ok

Yep, same on my RF. The reservoirs are quite angled when the bars are straight ahead, so the fluid can appear lower than it really is (when the bars are rotated so the reservoir is level).

[The Stranger:Me]

Yes I have braided lines.

[Colapop]

Yep, same on my RF. The reservoirs are quite angled when the bars are straight ahead, so the fluid can appear lower than it really is (when the bars are rotated so the reservoir is level).

I couldn't wait, so I topped up the brake reservoir last night. checked that everything was straight and level ...etc. It didn't need too much. I worked the lever a bit to make sure there were no bubbles. I'll properly bleed both brake and clutch lines this weekend... or tonight if I can't wait that long.