Jump to content
SAU Community

Recommended Posts

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

Link to comment
https://www.sau.com.au/forums/topic/214209-brake-fluids-motul-51-and-rbf600/
Share on other sites

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

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...

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....

Exactly what swanny180 said.. Same here :D

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 by siddr20
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

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 :P

Thanks for the advice.

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.

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.

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?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • That is surely the biggest gathering of Stageas in North America, ever!
    • Remember kids - if you can't afford to buy 2 GTRs......
    • I know people cry at the price of the Getrag 12-14k for a conversion now, but it really is a nice mid point. Not going to get change from 10k on a gearset installed.  $30k++ for sequential.   I know you run the risk of a damaged used one and parts are hard to get but as a street car gearbox its really hard to beat. If you enjoy a more traditional manual, its the choice no question.     
    • Time to decide what’s more import, your power level or your budget because you’re going to struggle to keep both 
    • Our Southern Highlands Cruise is proudly registered with “R U OK?” Day.  Sometimes the best way to check in on your mates is by getting out for a drive together. Sharing a common passion like cars creates the perfect space to chat, connect, and support each other.  A simple “R U OK?” can make all the difference. Let's enjoy the drive, the company, and look out for one another. PLEASE WEAR YELLOW FOR “R U OK?” DAY Sunday 14th September 2025 9:30AM Meeting Crossroads Homemaker Centre 10:00AM Cruise Departure Via Old Hume Hwy 11:45AM Arrival at Mittagong RSL Club Meet Location: Crossroads Homemaker Centre Final Destination: Mittagong RSL Club *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
×
×
  • Create New...