Brake fluid

HemiDuty · Post by **HemiDuty** » Thu Jun 08, 2006 10:10 am

I was using the RBF600, but was STILL getting friggin fade, although not as bad as with cheaper fluids.

Anyway I am now going to try some ELF ($40+ per half litre

) racing fluid and see how that goes. If that doesn't work then it will be time to pull the brake system apart and swear at it a bit....

Will let you know how it went next week.

Stretchy · Post by **Stretchy** » Thu Jun 08, 2006 1:00 pm

RBF600 is the way to go.

The best brake upgrade you could do with stock calipers is a Brembo 19x20 Radial master cylinder. Unfugginbelivable difference.

Stereo · Post by **Stereo** » Thu Jun 08, 2006 4:58 pm

HemiDuty wrote:I was using the RBF600, but was STILL getting friggin fade, although not as bad as with cheaper fluids.

Brake fade is caused by brakepad temperature though, not the cables/hydrolics ....... In fact dot4 and dot5 should be completely indifferent to what temparature it is (up to a couple of hundred degrees anyway)...

But yes.... Dot5 is the way to go.... someone else mentioned why earlier.... no moisture absorbsion.... (water compresses, causing worse braking)...

Post by **MadKaw** » Thu Jun 08, 2006 5:26 pm

Minimum Specification Good Brand Min Spec
DRY WET
DOT 3 205 Deg C 140 Deg C
DOT 4 230 Deg C 155 Deg C
DOT 5 260 Deg C 180 Deg C
DOT 5.1 260 Deg C 180 Deg C

HemiDuty · Post by **HemiDuty** » Fri Jun 09, 2006 9:24 am

The thing I have heard about DOT 5 is that water can get into the system, and because it does not mix with it you end up with a water 'section' in the line, like a little bubble of water with fluid either side of it, and this water will of course compress when you go for the brakes.

Oh and my brake dramas are a combination of fade and lever travel, but the lever part is the worst of it for sure. I might swap master cyls with Stretchy on the weekend when he isn't looking and 'test' the radial jobbie....

Steve_TLS · Post by **Steve_TLS** » Mon Jun 12, 2006 9:15 pm

HemiDuty wrote:The thing I have heard about DOT 5 is that water can get into the system, and because it does not mix with it you end up with a water 'section' in the line, like a little bubble of water with fluid either side of it, and this water will of course compress when you go for the brakes.

It can be worse than that. The moisture / water pools at the bottom, it causes corrosion and when it gets hot it boils. A "wet" hydroscopic Dot 4 or 5.1 will have a better boiling point than a Silicone based DOT 5 with water separated and sitting in the system.

DOT5 Silicone fluid also feels "spongier" than the others.

(It's a fluid / system you'd want to refresh often)

HemiDuty · Post by **HemiDuty** » Tue Jun 13, 2006 9:25 am

Well the ELF stuff went better than the Motul.

So it looks like my racebike really does have expensive tastes.....