[QP Sport]

I am planning on going to the Poconos for the Italian car weekend. Reading other posts, it was suggested one might consider using a "racing" brake fluid if considering running the track. The QP owners manual stipulates DOT 4. Is the racing fluid previous posts are referring to DOT 5? If so, why wouldn't Maserati specify DOT 5 in the first place?

My understanding is that DOT 5 being a silicon based fluid is non corrosive to body paint, non hydroscopic therefore longer lasting, and has a higher boil point. Why therefore would you not use it all the time? What's the downside other than you can't mix with DOT 4 and have to purge your system before replacing with DOT 5? Can it damage some components of the Maserati brake system?

[MaseratiBoy]

Call Jeff and ask for the Motul RBF600. It is a DOT4 that exceeds DOT5 standards...

Perfect.

[GCalo]

You cannot mix them! Dot5 is for racing and high temp applications only.

Stay with Dot4.

[Fred]

Use a Dot 4 or a Dot 5.1 fluid.
Dot 5 is a silicone fluid.

You are much better off with a fresh fluid than year old Racing Fluid.

[QP Sport]

Originally Posted by GCalo

You cannot mix them! Dot5 is for racing and high temp applications only.

Stay with Dot4.

I understand you that you can not mix them (i.e. glycol based vs. silicone) and would have to completely empty and purge system. But aside from that inconvenience, is there any reason not to use DoT5? e.g. is it too viscous at normal street operating conditions? Is it bad for brake components on street Masers, etc?

[Fred]

Originally Posted by QP Sport

I understand you that you can not mix them (i.e. glycol based vs. silicone) and would have to completely empty and purge system. But aside from that inconvenience, is there any reason not to use DoT5? e.g. is it too viscous at normal street operating conditions? Is it bad for brake components on street Masers, etc?

There may be an issue of seal compatibility with silicone fluid and the seal in the brake system. If the seals are not compatible with silicone the whole system will have to be rebuilt or some components replaced.

Other issues with silicone:
It is really hard to get all the air out.
Any moisture that gets in the system pools and corrodes the metal parts.

The best thing to do is to put fresh DOT 4 in before your track day.

[MaseratiBoy]

DOT 4 is hygroscopic and will absorb water... DOT 5 is not, so water will drop to the bottom of the brake system (the calipers)...

When the water is at the calipers, and you brake aggressively, it will boil and hydrolock the brakes. Hydrolocked brakes = death + expensive brake repair.

[GCalo]

Originally Posted by Fred

---You are much better off with a fresh fluid than year old Racing Fluid.

And from Fred "There may be an issue of seal compatibility with silicone fluid and the seal in the brake system"

All excellent statements.

Stay with the OEM and replace often if you are tracking.

[MaseratiBoy]

Again...

Motul RBF600 is a DOT 4 that exceeds DOT5 standards...

a DOT4 with boiling points above DOT5.

[fade2grey]

if you are looking for recommended alternatives, Castrol SRF seems to be king - if quite expensive. Not sure on the whole compatability question though...

[MaseratiBoy]

RBF600 is supreme!

[FormulaDynamics]

Motul is the way to go here. It's an easy pour in upgrade, we sell it with our brake upgrade kits. I've tested it at the track extensively against others. It's the way to go.

[2005QP]

Is there any difference between the RBF600 that says "factory line" on the bottle and the one that does not?

[scot]

I think you are thinking about it too much. ATE super blue and RBF600 are fine examples of great fluids. I used to switch between them on the track, easy to tell when you are completely flushed because of the colors. The dry boiling temp is similar.

Realistically the performance differences between the brands are very minor in respect to a track day in a non prepared vehicle. If you are a paid race car driver with a top notch system and pads designed for high heat use... then it starts to matter. In a QP with a regular person (even one with on track experience) is not going to get any benefit from one top notch brand over another.

Not saying get a cheap one, but any of the top of the line brands are great. If you do get a racing fluid remember to change it out after you leave the track. Most of them have GREAT dry boiling temps but are drastically hurt by absorbing moisture, which all fluids do but street fluids have other chemicals in them to keep them "dry" longer or just have higher wet boiling points.

[mazjag]

Dot 5 brake fluid while looking good on paper is something that never took off....I raced cars in BMW club racing and NASA for 3 season and we never ran that stuff.. The super blue or Motul like Scot said is the hot ticket..More important to flush it and pour in from an unopened bottle...my 2 cents..Jason