Brake Fluids Motul 5.1 And Rbf600

[PT]

Salesman at motor bike joint tried telling me that Motul 5.1 is a silicon based fluid???????

Now I know Dot 5 is silicon, and quick google search shows that the Motul Dot 5.1 is definitely non-silicon based

Question I have, not sure whether to get the Motul 5.1 or their higher temp RBF600 fluid, I'm upgrading the brakes on my S15 with R33 items new RDA slotted rotors and new TRW Lucas pads, the car has ABS and Motul advertise the 5.1 as ABS specific.

The car see's the track every 1-2 months, mix of drift and club track days depending on what I can fit in with

cheers

[swanny180]

Im using Motul 5.1 in my ABS equipped R33 with Lucas pads all round.

Gave it a solid thrashing at Wakefield the other day with no pedal fade to speak of - for $15 a bottle, I cant fault it

[Sydneykid]

Salesman at motor bike joint tried telling me that Motul 5.1 is a silicon based fluid???????

Now I know Dot 5 is silicon, and quick google search shows that the Motul Dot 5.1 is definitely non-silicon based

Question I have, not sure whether to get the Motul 5.1 or their higher temp RBF600 fluid, I'm upgrading the brakes on my S15 with R33 items new RDA slotted rotors and new TRW Lucas pads, the car has ABS and Motul advertise the 5.1 as ABS specific.

The car see's the track every 1-2 months, mix of drift and club track days depending on what I can fit in with

cheers

Why are you using ~600 degree brake fluid with ~300 degree pads?

Cheers

Gary

[some_cs_student]

Why are you using ~600 degree brake fluid with ~300 degree pads?

Cheers

Gary

Hey,

It was recommended to use RBF600 for track days, to avoid the fluid boiling, is there any disadvantage to using it over say Motul dot 5.1?

I'm planning on using some better pads next time but my pads are not rated close to 600 degrees...

[ferni]

Well RBF600 is just rated higher temp than the normal 5.1...

If you're still on street tyres and street pads you shouldn't be boiling any decent DOT4 brake fluid. The Motul 5.1 or RBF600 will be fine as well....

[siddr20]

Exactly what swanny180 said.. Same here

Except im still using stock nissan pads which bite just as well on track (has been proven both times i have been out there with the quickest time of 1.13 on stockish 33)

Edited April 12, 2008 by siddr20

[Sydneykid]

Hey,

It was recommended to use RBF600 for track days, to avoid the fluid boiling, is there any disadvantage to using it over say Motul dot 5.1?

I'm planning on using some better pads next time but my pads are not rated close to 600 degrees...

The issue is that the pads will stop working (fade) long before the brake fluid fails (boils). So spending (waisting) money on ~600 degree brake fluid isn't going to give you any benefit. You might as well save the money and buy some ~300 degree brake fluid this time. Let's face it, you are going to have to change the brake fluid when you put the new (~600 degree) pads in, so you might as well only spend the extra money on the ~600 degree brake fluid when you actually need to.

R32/33/34 Skylines with their 4 spot front/2 spot rear brake callipers have fairly good heat transfer insolation from the pad to the fluid and, as long as you do a cool down lap, new/fresh brake fluid boiling is not an issue. It's when the system gets contaminated by water (brake is hygroscopic) that boiling becomes an issue. We use Castrol Response Super DOT 4 and have never had fluid boiling issues.

Cheers

Gary

[some_cs_student]

The issue is that the pads will stop working (fade) long before the brake fluid fails (boils). So spending (waisting) money on ~600 degree brake fluid isn't going to give you any benefit. You might as well save the money and buy some ~300 degree brake fluid this time. Let's face it, you are going to have to change the brake fluid when you put the new (~600 degree) pads in, so you might as well only spend the extra money on the ~600 degree brake fluid when you actually need to.

Point taken, I was going off advice from this forum from some people who recommended going RBF600 in the fluid.

I'll consider using standard dot 4.1 fluid next fluid change with some decent pads

Thanks for the advice.

[djr81]

Just understand that the 600 degrees for the brake fluid is in fahrenheit.

The 300 degrees for the pads is almost certainly celsius.

So the difference is actually only 15.5 degrees (celsius)

Never the less the point still stands. No point having million dollar brake fluid with 10 cent pads, or the other way around even.

[br3ndan]

i know its a little bit off topic, but i heard the dot 5 or 5.1 not quite sure, can eat away at the rubbers on your brakes system??

Whats the deal with this? is it true?

[djr81]

i know its a little bit off topic, but i heard the dot 5 or 5.1 not quite sure, can eat away at the rubbers on your brakes system??

Whats the deal with this? is it true?

Yes it is true. Some silicon based fluids are incompatable with the seals found in the braking system.

[MrStabby]

Yes it is true. Some silicon based fluids are incompatable with the seals found in the braking system.

So dont use 5.0 which is silicon. Use 5.1 which is not.

[br3ndan]

So Dot 5.1 in my R33 GTS T would be good?

Planning to swap out the brake fluid very soon.

[some_cs_student]

So Dot 5.1 in my R33 GTS T would be good?

Planning to swap out the brake fluid very soon.

I think the conclusion of the thread was go greater than dot 4 only if your doing a track day with good pads...(and even then, its unlikely to boil...maybe if your running semi slicks and track pads dot 5.1 is definitely a good idea).

Sydneykid, who does race advised that he uses Castrol Dot 4 without any issues at all. which is an interesting opinion, I have never boiled brake fluid so I'm considering going back to Dot 4 and seeing how it goes

Does that sound about right?

[br3ndan]

yeah, good idea, ill go with DOT 4, should be more then capable for street use. =)